I love those two shows! Alias can really suck me in. And my whole family is involved in watching AI - discussing people's strengths and weaknesses, who should get voted out next, etc. This is a great show - a singing competition, good clean fun.
Also my whole family watches Survivor. Smallville is good, too. And don't forget Everybody Loves Raymond! Those are my favorites!
(as far as all-time classics go: can't beat I Love Lucy and The Cosby Show!)