I have to disagree with posters who are dissing the current cast.
To me, Bill Hader is the funniest person to ever be on the show (and I'm a fan of all eras of the show). I start cracking up just seeing that guy before he even says anything.
I think that a lot of the new people are very strong as well, like Taram Killam, Jay Pharoh and Kate McKinnon. They have great presence and timing and quite a range of abilities. The writing and sketch concepts have been edgy and sometimes brilliant (although there are of course duds in this season as well as every season since the beginning).
It's easy to remember older seasons with rose-colored glasses. We tend to recall the best of the past and to forget the boring sketches that might have destroyed the pace of the show. When we watch the "Best of.." compliation DVDs, we're not getting a complete picture.
I would argue that the current cast has way less duds than in any previous eras of the show. Certainly the early 90s had a lot of weak sketches we're forgetting, as did the 80s. I bought all 5 original cast seasons on sale recently, and it's surprising how weak some shows are. Seasons 1 and 2 are particularly uneven.
Speaking as a big fan of the original 70s cast, the 80s cast AND the early 90s cast (like I said, I like all eras of the show), I would still argue that the current cast is the best!