I'll just echo what everyone else has already said. Seeing the 'Best-of' Collection come out seemed to pretty much spell the end of the Season boxed sets, without giving the show a chance to get to its best seasons.
Season Three is absolutely Mad About You at its very very best!!
The show's very best episodes are here in Season 3:
Our Fifteen Minutes, Two Tickets to Paradise, Cake Fear and the show's absolute best moment, the hour-long season finale (an 'Its A Wonderful Life-ish') 'Up In Smoke', where Jamie and Paul see what life would have been like if they'd never met.
The stars are at their very best, and the supporting cast is given its best work in the show's run. The quality of Season 3 is so high, that the 'good' work in the remaining seasons pales by comparison.
So, it's good?
That's what I'm saying.