M*A*S*H
All in the Family
The Odd Couple
Frasier
Roseanne
Barney Miller
Taxi
The Middle
Modern Family
Murphy Brown
Honorable Mention: WKRP in Cincinnati ("I thought turkeys could fly" alone earns a mention) Everybody Loves Raymond (Doris Roberts and Peter Boyle were awesome) The Golden Girls (too many jokes I can't relate to, but damn funny with a great cast)
The first two or three years of Friends were top-notch, but after that you just wanted to beat the crap out of every one of them. Mary Tyler Moore was both excellent and culturally important, but just not quite on the level of the top 10, IMHO.
And Speechless has a chance. Much like The Middle and Modern Family, the kids' roles are both very well-written and very well-acted.
But speaking of well-acted kids parts, why was Sara Gilbert so awesome on Roseanne and so lame in the past two sitcoms she was in? Have you tried watching Living Biblically? Remember Bad Teacher? Yikes. (Although Living Biblically did solve one non-burning question: Whatever happened to Burt Reynolds' kid on Evening Shade.)