The Colfax place is the Cheeky Monk. Good Belgian food, but the beer menu - while impressive - is a bit overpriced IMHO considering you can pick up 3/4 of the available beers at many of the local area liquor stores. With lots of great places to choose from, the Monk would not be on my "must see" list. I'd add Bull and Bush to the must see list (about 20 minutes from downtown). Breckenridge brewery, particularly the Kalamath location (5 minutes from downtown) has great BBQ and is another solid choice. The downtown location right across from Coors Field has the same beer, but the food is better at Kalamath. Pints Pub is also downtown (off of 13th by the art museum) and brews their own. They don't distribute - can't even get a growler to go last time I checked, but they have some really good brews and the atmosphere is nice.
Argonaut Liquors on Colfax is also a great place to top by and peruse the available beers.
If you make the trip to FoCo you'll drive right by Longmont which has a branch of Oscar Blues (the other location is in Lyons), Left Hand, and the Pump House. All three are very good choices and worth a detour.
You could also opt to skip FoCo and head up to Boulder, about 1/2 the distance from downtown when compared to FoCo, and hit up Avery, Mountain Sun, Boulder Beer, Redstone Meadery, Twisted Pine, BJ's, Walnut Brewing (a branch of Rock Bottom) and Upslope.
There's not much out in Aurora - but Dry Dock was last year's Small Brewery of the Year and well worth the time for the trip that way.