I am planning on buying emerald soon, and I just needed to know some stuff about the game...

Can you trade in the games back to G/S/C and R/B/Y, cause I have heard that you can't. and the wireless trading, does that work for R/B/Y and G/S/C?

What pokemon from earlier generations are really good stilll? (I have beaten Blue with all 151 gameshark free, and what pokemon on G/S/C are still good. So that I can trade my best pokemon back over.)

Finally: out of the newer generations of pokemon, which ones our the best? (I don't know anything about any of the newer pokemon.)

thanks, sorry for asking noobish questions, but I need to get caught up.