Not funny for at least 20 years.
Actually, they were never really funny. People (including myself) have fond memories of the early years with so many comedians that went on to be stars, but even in the early years, the show actually sucked. They had maybe 10 skits every season that were funny at the time, but if you go back and watch them, it's incredible how amateurish they were. Try watching a full show, not just one skit of the 20 or so "classics" that are memorable.
If you just watched the "best of SNL" that plays every New Years Eve, you would think it was a great show. Kind of like a trailer for a 2 hour movie, where you see the best 2 minutes of the show, and the other hour and 58 minutes are terrible.