What do you mean by contemporary, 50s or 70s onward? I'm much more familiar with the earlier part of that century (filled to brim with excellent stuff IMHO), but I've found some more recent works to my liking too. Out of the A+ stuff, I'd have say the Ligeti piano études (compares very favorably with the great études from past eras) and maybe Carter's Night Fantasies (though I'm not sure that it'd be well liked around here) and some of Xenakis' chamber music works. I don't have the time right now, but I'll try to upload some of this stuff later.