Fire Emblem's Radiant Dawn and Path of Radiance
 

Would I need to play Path of Radiance before going on to Radiant Dawn?

I would say that it'd give you a deeper appreciation for Radiant Dawn, but I really doubt it's even necessary. I haven't actually played Radiant Dawn yet, mind you, but I know that it takes place several years in the future. Sothe, a young thief from Path of Radiance apparently plays a part in Radiant Dawn as an adult.

Regardless, Path of Radiance is still a great game so I recommend playing it. You should be able to find it for pretty cheap too.

Path of Radiance to Radiant Dawn is like Golden Sun 1 to Golden Sun 2
you start RD with different characters but all (but one) of the playable characters from PoR will come back
You'd miss out a LOT on the story if you don't play PoR first, also there are bonus for transfering save from PoR to RD

Thanks for the heads up :).

There's glitch that you can't upload the files ~__~ from previous.

That glitch only applies if you have a save file present on the "easy" difficulty. As long as your memory card only has "normal" or "hard" data, you'll be fine.

Looks like I'll be fine, then. I'm actually surprised by the relationship between PoR and RD.. I figured it'd be more like the relationship between FE7 and FE6. Well, regardless, I really need to get this game. And a Wii, of course.