Wholehearted agreement on the Monkeys, Carpenters (playing their Christmas album last night), everyone bigrun mentioned, and especially Three Dog Night. My fave:
http://www.youtube.com/watch?v=fZ1tF6LgB40
Gosh, I'm feeling more mainstream than evah!
Don't forget the Doobies (this song really gets the synapses sparking)
http://www.youtube.com/watch?v=c_iTbzc2K4U
Does anyone know who wrote the lyrics in my sig below?