I first got into Pantera around age 9, when "Cowboys from Hell" was first released. I tricked my mom into buying it for me some how some way, and from there I was hooked. I saw them live a few times, and I feel they are the Black Sabbath of my generation. Not sure what albums you have, but they are all worth listening too as all are very different and showcase the ever inspiring guitar playing of the late/great Dimebag Darrell. Here are some metal bands you can check out if you like Pantera:
Killswitch Engage
Lamb of God
Mastadon
Between the Buried and Me
Avenged Sevenfold
System of a Down
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Douglas Showalter