There are a lot over the years that have made an impact, but probably the two I remember above all else.

Jaragh- someone who I really tried to emulate with my leadership style

Robilar- one of those people who epitomized what a paladin should be.

both of these are from when I was still a mortal, but for me to even start to list off people that I've watched as an imm that I thought brought a lot to the game, I know I'd miss some important folks.