A mild, lower gravity Belgian blonde, lower OG pale ale, a hefeweizen, an American wheat, or an English bitter would all work.
The keys- pitch plenty of yeast! Consult mrmalty.com for the pitching calculator. Keep fermentation temperature under 70, but above 64. Use a highly flocculant yeast (S04 comes to mind), and don't use a ton of complex ingredients. I'd stay away from stouts (due to the roasty flavors that can need time to mellow), any beer above 1.050 or so, and anything with spices.
Otherwise, you can make many different beers!