Much of the interesting stuff is located downtown on Pearl St (outdoor walking mall). If you want 'average' food, the staples are the Rio Grande
and Walnut Brewery
. Decent places, always full enough to seem lively. Walnut is actually the model for the Rock Bottom chain - slightly better than Gordon Biercsh IMO- Beer OK, - feels like a typical boulder place to go out, better vibe than any rock bottom.
Rio is famous for it's margaritas (there's one in denver too). They aren't superb, but are famously super strong. One of the best rooftop patios in Boulder and the bar is very lively until about 10 or 11pm when they close. it can become very interesting after people have put a couple drinks down. so there are better margs, but the rio hits the perfect price range to get college kids housed.
-Places with classier food and some good drinks:
West End Tavern(west pearl) - kind of a smaller menu, definitely not pub fare, maybe upscale American? Lots of great beers on tap and they have something called the 'bomb shelter' with a vast selection of rarer 22 oz bombers from craft brewers across the US ($20-$30 bucks even). Lots of Bourbon, a nice covered patio bar upstairs, open patio in the back with mtn views (must get food, can't do just drinks in back).
tahona(west pearl) - more upscale mexican food than the rio. not 'authentic' fatty gut bombs, but some good stuff. sometimes a band after 9. lots of tequila.
St Julien Hotel - has as nice outside patio with happy hour on fridays. Huge teraced patio has great view of the mountains. Can't see doing more than a couple of drinks here.
restaurants that might be better for drinks than food-
bacaro(west pearl) - i think the food used to be better, but it really looks like it should have good food. used to be very dance club like after 10pm in the back room. upstairs has a nice patio and you can look down on the street and watch the bouncer bounce people later at night. it might have more of a sorority/fraternity vibe (i'll refrain from calling it douchey, but...), and it is really amusing to see it fill up with college kids getting hammered while the older crowd is still finishing off their meals.
Centro(west pearl) - former restaurant was so famous it's mojitos that they kept them when it re-opened with a new menu. cool little outdoor patio bar section. not open super late.
Some restaurants (likely need reservations):
The Kitchen (and kitchen upstairs) - very nice restaurant. still not super pretentious. local and organic food. hate to compare to chez panisse, but along those lines and a little easier on the wallet. huge beer list with some absolutely crazy beers.
(walnut st) - tapas and a lot of other Mediterranean food. nice coutyard patio. great happy hour before 6pm. can't go wrong here, though it gets crowded and can be noisy.
Dushanbe Tea House - building was built by Tajikistan artists, lots of hand crafted things. funny because it was an 'sister city' exchange with the city of Dushambe, and they got something really crappy from Boulder. good food.
Pasta Jays(west pearl) - simple italian. I like it more than a lot of the more expensive intalian restaurants in Boulder (and there are a lot of those).
Jax Fish House - the old head chef won Top Chef a few years ago. seems a lot more crowded even though I don't think he works there anymore. I've been disappointed often by seafood in similarly priced places in Boulder - that wasn't so at Jax. a little small and crowded.
Salt is a new restaurant right downown too... supposed to be decent.
Foolish Craigs(east pearl) - slightly less of a pretentious vibe, still good food.
Black Cat as twister recommends is supposed to be really good (never been). Meals are $20- $35 so getting to $130 a person is a lot of wine.
Also, some mid priced places away from pearl st where I've eaten and would go back: Arugula, Laudiso, Alba, Zolo.
There are lot of more expensive places that I've never been to...
later night bars:
- typical irish bar, live music later in the evening, smaller outdoor patio in back. probably people doing car bombs all night.
Pearl St Pub
(pearl st mall) - probably the most 'local' of the Pearl St bars, downstairs basement with separate bar and a few games (foosball, darts and pool downstairs + some video games). very strong drinks. people might call it a dive, but it's really not. CU tradition is to kiss the buffalo on 21st birthday. a slightly older crowd so it doesn't feel like a college bar all the time.
aka the downer (pearl st mall)- compete crap hole, but for some that's a good thing. 'trendy' dive bar is what I'd call it. another basement bar, smells kinda funny. cheapest pitchers of PBR in Boulder (I could be wrong, but it tastes stale compared to other places). Row of 5 pool tables. Not quite hipster, but not fratty by any means.
- yet another basement bar under the Hotel Boulderado. again not a dive, good drink specials, can't quite describe the vibe, lots of little rooms with different things going on - game room, a couple of pool rooms, a couple of bars, sometimes a DJ.
Walrus (walnut st)- the kips of Boulder but with peanuts and foos and pool. cheap beer and a great place to find some roofies. I don't really know why anyone over 21 would be there (OK maybe 25), but I say the same about Kips and have been back too many times.
Round Midnight (west pearl)- seems like the only place in Boulder left that has a true dance floor. Not really full on club like, but has bands and/or a DJ. I've always thought it was a strange crowd.
For those staying near the southeast side of campus, the darkhorse is worth checking out. famous for the tuesday night trike races. quaint place, I think it's the only place I've been recently in Boulder with Big Buck Hunter. It might get kinda depressing a lot later at night when people head downtown, but pre and post game should be full and is generally fun.
Shooters is a bar near conors with a riding bull. seems a little strange for boulder, but just throwing it out there. perhaps that's your thing.
The Attic - decent place - not as crowded as other places, not really any theme, but a decent crowd, not dingy and they have alcohol. One of the later last calls, though I haven't resorted to that in awhile.
On the Hill (younger crowd):
K's China - rooftop patio, cheap drinks, I've never been inside actually, but last time I was there a friend passed pitchers though the emergency exit on the patio cuz they weren't letting people in (dont tell the cops).
The Goose (former La Iguana)- has a awesome patio, I'm feeling too old to really go back.
And then there is always the Sink
. beers, pizzas, sandwiches, pasta, low ceiling and 40+ years worth of scribbling on the walls. Robert Redford used to work there when he was a CU student. The hill used to be more of a scene (maybe stuff goes down still, i'm just too old, and maybe it's the MMJ, but riots and couch burning just aren't as big now), but the sink is a classic.
When 2am rolls around and you get booted on to the street, there are a few places for late night food (after 2am)-
-The gyro stand near Old C's (never had one sober, but they are tasty).
-dubbins - a literal hole in the wall (4' wide and 6' deep) sandwich shop, 13th street right off mall, near catacombs and conors
-pizza colore - slices pizza will get the job done, not blondies though, on mall next to lazy dog
-cosmos - better than colore, by the slice (or deliver), on the hill and also on baseline and 30th near the dark horse
- illegal petes - on the hill and on the east end of pearl st mall(warning that one closes @ 2am). Burritos and similar stuff to chipotle but better. it feels a lot healthier than a burrito from the mission, who knows if thats the case.
Some other places:
The Mountain Sun (and Southern Sun, which is much larger) is another local brewery with some good beers and a definitely a hippie vibe. Guaranteed to see someone wearing a woven hat. Java Porter seems to be everyone's favorite beer, but they have a whole range. cheaper pub type food and sandwiches, but decently quality.
Old Chicago has an great front porch patio with great views of the busiest corner of the Pearl St mall (and full bar). Always good to check out people of all different varieties (from coeds running to the bar to some bums wandering around aimlessly and maybe even yelling random sh1t... just like at Cal!), but it's not like anyone would just drive to boulder for the food there.
The lazy dog is an OK sports bar on the east end of the pearl st mall, good place to catch a game, only real sports bar around. Nice patio on the roof (but the mountain view isn't there) and I've never figured out why its crowded some nights and empty others.
Also, if you like beers of the ale and strong ale variety, Avery Brewing
is a smaller Boulder based micro that has just been exploding recently. They have had to pull back distributing from places like Northern CA due to too much demand. Very interesting brews, lot of specialties - they have a tap room in an industrial park in Boulder (their more mainstream beers should be available on tap everywhere... some other ones are just in bottles). If you want to go on a mini micro beer tour, Twisted Pine, Upslope and Boulder Beer are all in town, if you are around sunday evening, this looks like a great way to visit the breweries w/o driving