Me? Uhh... Sphanx Pure BD Craft with the sound packs and all. But I'm keen on trying out other texture pack. Basically, realistic resource packs are pretty but somewhat ugly without additional visual modifications like realistic shadows and lighting and such... Which isn't really good for my PC. On the other hand, cartoonish resource packs are kinda off to me. I think the resource pack I'm using kinda stays in the middle of the two but... Yeah... I'm keen on trying out other resource packs. I'm definitely trying the Soartex Fan Version one since most of you here use it. XD
I usually play in vanilla style, so no texture packs at all. I used to experiment with Chromahills but grew a bit weary of that due to the required resources and well... I can't help think that the glowstone and redstone lamps look a bit funny. So then "someone" (Hi Blinky! ) suggested to look into Soartex and yeah... The other resourcepack which I like is Faithfull. And those are basically the only two I sporadically use.
I personalize some blocks and use this pack: http://mods.curse.com/texture-packs/minecraft/231802-x-vaders-alternative-block-pack-over-350-random