Gay cruise -- no contest.
Been on one straight cruise -- was ok, but like going to disney land in that there were kids running/yelling/screaming everywhere, parents who didn't seem to care what their kids did and bland entertainment aimed toward the "family" level -- think Bob Sagat humor, etc.
Then did a gay cruise -- so much fun. Parties if you want them, quiet spaces if you don't. Adult, fun entertainment (no, that isn't a code word for strippers, just adult sensibilities). Lots to do or do nothin and switch it up as you want.
Also, gay cruises (at least the Atlantis ones I've done) are far less formal than a standard cruise. There isn't assigned seating at dinner -- sit where you want, eat when you want (within the general window of dinner hours -- there are always buffets available pretty much 24x7). You can dress up for dinner, but most folks don't, so it's really relaxing.
In the end, in most ports where we pulled into next to a straight cruise, the folks there looked relaxed and bored and were staring longingly at our boat which was pretty fun even when sitting in port.
Plus you can totally relax and hold hands, kiss, be affectionate, etc and everyone is super friendly.
Won't waste my time on a straight cruise again.