I used to use HD Realism, but it took the fun out of the game. I now always use default.
Texture Packs

Lately I've been really busy making my own texture pack! I finally finished it yesterday after 6 months of work. I made many of the more unique and important textures myself (swords, rod, bow, flint and steel, golden apples, gravel, sand, grass/dirt/mycelium/podzol, stone/ores, cobblestone, particles, etc.) and so far everyone who's used it has said it's one of their favorite, if not their favorite pack! This is the first pack I've ever made that I am actually proud of. If you guys want to check it out, here's the link! (BTW, this pack has almost 50 downloads. Before that my most downloaded file had 5 downloads xD This pack is starting to really take off I can't wait to see where it goes)
http://www.mediafire.com/download/7f1bg5x1g7k2czg/Arcenim%27s+Pack.zip
What texture packs do you use? I used to only use default, but lately I've been using the "Plast Pack": https://oc.tc/forums/topics/51040da0f34422dbb400012c