Alex Lifeson - some argue he is appreciated, but I argue he is just well known. If I had a dollar for every time I have heard "Lifeson sucks"..
Gordie Johnson (Big Sugar) - Awesome player, very versatile. Can play anything well..blues, hard rock, you name it.
Howard Leese (Heart) - A bit arrogant, he is a well above average player and was a major factor in 25+ years of classic Heart songs...and gets props for never getting fired. After the Wilson's, most people have no clue about other Heart members.
Agree with Rocky George and Kim Mitchell...especially Mitchell. Outstanding player.