of course, i gotta plug my store, Gimme Anime, 60 South Havana, #601, Aurora. it's a bit of a drive from LoDo, however.
restaurants: bump & grind, 17th & logan (i think?). they have an awsum brunch on saturday, though i hope you BF doesn't mind cross-dressers. i recommend the cheesey-estraada. if you like sushi, there's a sonodas in downtown. however, if you want REALLY good sushi (though with terrible service, i have to admit) check out domo's on 10th & osage. i used to work downtown, so i'm pretty familiar with the area.
as for clubs, there aren't any, really, that aren't attached to a college. the last one, DAI (Denver Anime International) disbanded a couple years ago, since they're no longer really necessary with downloading and streaming anime.