i grew up with the late 80's early 90's metal (T'allica, Exodus, Slayer, Testament, Pantera,) but as soon as the Nu-metal fad (Korn, Limp Bizkit, you know the ones) hit I didn't buy a metal cd (or any cd for that fact) for about 4 years until i went on a trip with my work, met a lot of yanks who put me onto these bands. These are the bands that have turned me back into metal and there is a bit of variety here. My missus is a yank so I definetley have a slightly more american flavour to my selection because of the fact I have to go over there once a year and get advice from the locals.
Killswitch Engage- End of Heartache, Alive or just Breathing (metalcore, but it is good)
As I Lay Dying- An Ocean Between Us (I havent heard an album this good in a long time)
Chimaira- The Impossibility Of Reason (check out "Pictures in the Gold Room", "Down Again" "The Dehumanizing Process")
Trivium- Ascendancy (the newest one is $hiiiiiite, avoid the Crusade)
Bullet For My Valentine- The Poison, Scream Aim Fire (Welsh lads, sounds old school)
Lamb Of God- Ashes of the Wake, Sacrament.
All That Remains- The Fall of Ideals (metalcore but like KsE, very good, check out the song "This Calling" or "Six")
Nile- Ithyphallic (middle eastern style death metal, sounds weird in theory but they are excellent)
Arch Enemy- Doomsday Machine (chic singer, great guitars)
Still Remains- The Serpent (they look like emos so you would want to punch them, but this album, whilst slightly softer, has some excellent songs, check out "wax walls of an empty room" "Stay Captive". As I said, they aren't exactly metal, but quite catchy. Not for everyone.
Anyways I hope this helps, there's a little bit of variety there, hope you find something you like
Beaves.