If you haven't done the New Belgium Tour I highly highly recommend it. Another vote for Odell's and also, right next door is Fort Collins Brewing which I heard good things about, but didn't get to try while I was there.
Fort Collins Brewing mostly relies on their range of staple beers which are right down the middle in quality. Their special releases and brewery-only beers are solid though. The food is also excellent. When I make it up to Fort Collins I usually start here for lunch.
There's quite a few breweries in Fort Collins. Horse and Dragon has some interesting beers. Funkwerks does a good job with their saisons and various other Belgian beers. Zwei on the south end of town has some solid German offerings. I think Prost's tasting room is also open now. I wasn't a huge fan of Equinox outside of their oatmeal stout. Several other breweries in town I haven't tried out yet. I'd give another vote to Odell.
Prost and Zwei might be good options if Corona and Fosters are your preference for beer.
New Belgium's tour is great even if you're not the biggest fan of their beers but you have to register for tickets far in advance.