Welcome to Taiwan and the shortage of good microbrewed beer.
For the U.S. microbrews you'll only find Rogue, Anchor Steam (quite a few flavors and found in a number of places), and Saranac (at RT Mart). You can throw in Samuel Adams lager at most 7-11s. Other than those, the rest of the American brews fall into the panther piss category (Bud, Miller, etc.).
There's quite a number of trading companies, though, that sell Belgian brews on their websites, as well as a number of cafes around NTNU and NTU that sell many different Belgian beers.
Nonetheless, this year's summer beer-fests at 7-11 and elsewhere are actually rather decent, versus past summers' offerings.