Well, our other DM is starting up a 5e campaign, and I'm currently running a 3e one.
I'd like to try something different, so we don't have 2 5e games going at once. Right now, I'm leaning towards C&C, because it has a good mix of old school feel, and D20-ish rules. Also, the art on the tribute cover releases rocks! Not to mention that it's billed as being easy to convert adventures from all editions of DnD to, and I have 2 of the supplimental monster books, lol. The one, Creature Codex, continues to fill me with maniacal glee, at springing some of these things on my players. (whoever their designers are, they're just as twisted as we are!)
Just to top it off, I ended up with an extra player's guide- so I have an extra for my players to use. (I got the first, thinking it was a standalone book... Later, I got a good deal on the full set of all 3 tribute cover hardbacks.)
However, I'va also just gotten my hot little hands on Dragon Bane's box set. Haven't cracked it open yet, but I like what I'm hearing. The cover art is stunning!
I also have OSE and DCC for options, but right now, I'm leaning towards one of the above.