Yeah, I understand >.<
Well, some portable systems can look really good at 15" or 13" (17" is just... far too big for anything in my opinion).
Most portable games tend to look better on their original systems with the original size, GBA games for example, you can use filters to make them look smoother, but they lose some colour quality in return. For DS games, I still haven't seen a single benefit emulation wise. Psp does have some benefits, due to some filters, but a lot of games aren't compatible with it.