At The Gates is an awesome death metal band. Although they broke up in the late 90's. You can tell their influence is very strong in the metal of today. I got their album Slaughter Of The Soul last year and I thought it was a new album since it sounds like a lot of the stuff out now. I had it for like six months until I found out it was an 11 year old cd. Last week I saw the band made up of most of ATG's lineup, The Haunted. It was one of the best concerts I have ever been to. Although they are more like hardcore now.
If you want some great melodic death metal, check out In Flames, Arch Enemy (singer is hot), and Soilwork.