All of them are pretty sweet. I liked Red Rescue Team and Explorers of Sky, and out of the Wii versions I prefer the fire one simply because you can start as Vulpix, Charmander, Cyndaquil and Eevee, even though I haven't played it.
Of course, I'm looking forward to the Gen5 releases. Hopefully, they'll turn it into a more dramatic game with better graphics.