Rate my channel and thumbnails

[UltraKrillin]

When my brother and I decided to make a channel we wanted to have a piece of us in everything we do. I included a dbz theme because that anime really was our childhood and our favorite characters are krillin and gohan. I would also like your opinion on my thumbnails. There all different so you can tell I've been experimenting. Any opinions and advice will be welcome.
http://www.youtube.com/user/BrothersGrimmTV

Thanks guys