The blockchain.info wallet and the Android wallet by Schildbach (if I'm not mistaken). Most of my holdings are kept in a paper wallet, laminated, and placed in a folder. 
Old school, huh?
I use blockchain too for all of my bitcoins, but I don't have enough for me to worry at night about wallet security. Blockchain.info is definitely more secure than the alternatives and I like the fact that I can access my bitcoins anywhere.