In my professional opinion, the only thing that Mr. Rogers' Neighborhood has going for it is better graphics, almost photo-realistic even. For the time, the graphics were unreasonably good and can hold up even by today's standards. However, the terrible gameplay completely destroys this game. To start with, Mr. Rogers' Neighborhood doesn't even HAVE gameplay. The closest you can get is by going to http://pbskids.org/rogers/games/ and doing the lame little flash games that inhabit that part of the internet, but that isn't really gameplay in my opinion.
However, Shrek Super Slam offers the best of both worlds. The graphics, which may not be great by today's standards, were groundbreaking at the time and had people asking "Are you watching a movie or playing a game?" The gameplay, on the other hand, is more than groundbreaking. To start with, it offers a gameplay mechanic that few games managed to replicate until quite recently: fully destructible environments. I'm not going to tout that as the main selling point of the game, but it was extremely unique at the time and something that has aged reasonably well. The main gameplay was a perfect combination of easy to learn and difficult to master which lead to a great community scene competitively. In addition, the characters and storyline were both believable and lovable, which is always a huge selling point for games.
In conclusion, Shrek Super Slam is the best video game in the world and Mr. Rogers' doesn't even come close.