It really depends.
I enjoy hand painting them, but I also really like the pre painted PE. I'll rarely ever use a decal, more often than not, they're pretty silly looking. Another option...IP's from Yahu. These are cheaper than PE (but all you're getting is the IP). I haven't put one in a plane yet, but I have purchased at least a dozen, and stashed em in with their respective kits. These look amazing...I'd say even better than Eduards PE.
http://yahumodels.siemianowice.com/