Wii section's weird, moved to general since it's going to talk about a few.
Anyways as far as portable systems go, there's better than the PSP in the form of those Dingoo/etc. handhelds, but even the latest models aren't as cheap as a used PSP, and they have some of the same drawbacks (low resolution, etc.) so many people go for android if they need portability, though getting a device with good controls means you'll be reading a lot.
There's also consoles, the Wii's emulation library is pretty well-developed, the PS3's more powerful but doesn't have as much development life under it's belt so which emulators work better could be a tossup.