OverKill: The Years of Decay, WFO, etc... Most of their albums are worth having. I have just about all of them. There are only a couple I don't like a lot.
Testament: Again, ALL of their albums are worth owning (well Demonic isn't the best). If you want a newer album from them get THE GATHERING. For an older one get THE LEGACY and PRACTICE WHAT YOU PREACH. Another band whose albums I wordhip!