Anything Fire Emblem is amazing. Even the mediocre games are head and shoulders above most other games that come out nowadays. With all these new games coming out, I'm still playing Fire Emblems for Game Boy Advance!
I don't like to compare, but since Radiant Dawn is a direct sequel, I have to say that Path of Radiance is 10x better. Also, don't worry about playing it on easy... Fire Emblem games usually have an unforgiving difficulty.