I personally like the grob opening, especially for blitz.
It goes: 1. g4
And, just an example of a continuation: .. d5 2. Bg2 Bxg4 3. c4 e6 4. Qb3
I also like using the same idea as black playing against 1. e4. For example: 1. e4 g5 2. d4 Bg7 3. Bxg5 3. c5 4. Be3 Qb6
The computer evaluation isn't always sound, but in practical play (in blitz), it works pretty well.