there's the A-Team, then there's everything else as far as sitcoms/dramas go
but I also like
Magnum P.I.
Simon & Simon
Sanford & Son
WKRP in Cincinnati (including the closing theme)
Cheers
M*A*S*H
The Greatest American Hero
Welcome Back Kotter
But, if the Olympics count, John Williams' Olympic Fanfare and Theme immediately becomes my #1.