Edguy > Hammerfall. That's a huge understatement. Quite arguable that each band is past their prime, but let me take a moment to compare my favorite album from each band.
Edguy - Hellfire Club. One of my favorite albums of all-time, easily in the top 10, and was an album that somewhat redefined music for me when I heard it in 2004. I still listen to it once in a while and love and respect it.
Hammerfall - legacy of Kings. Top 100 Album of All-time, at VERY best. Probably not even that high, on a good day. When I was 15 I thought this band was incredible, but as time has gone by, very few have faded in my mind quite like this one. Even their best work is merely solid and fun.
Basically, I can still listen to Hammerfall once in a while for luls and such, enjoying their music if I don't look past the cliche shell of it. They could break up tomorrow and it wouldn't sadden me one bit, but I will still go see them if its convenient, occasionally watch a DVD, or put a CD on. However, Edguy have evolved into one of my favorite bands of all-time.