Yeah, Isaac is fantastic! I really need to get around to playing Rebirth... Spelunky is my go-to for non-ascii roguelikes though – really nicely designed game, worth a look if you haven't already.
Rebirth is excellent. I would say it is much better than Wrath of the Lamb. I own Spelunky too! I watch a lot of Youtube videos about Spelunky. Have they updated it recently?
Nice one :-) Trying to do speedruns is the way to play it, I find (though I'm not great by any means). They've released it on more platforms, like PS4 and PSP, but there haven't been any updates. I think the developer wants to leave it at that for that game; I've no problem with that, but I wouldn't mind another solid roguelike platformer. Vagante looks like it could be next.
I checked out Vagante last night. It's pretty solid in it's alpha already. I am legitimately excited about the official release. Super fun.