I love Seasame Street and my kids do too. It's educational and has enough going on that it's not boring for adults if you end up watching it with your kids. I also love that it shows a bit of ethnic diversity and often explains some fairly serious topics in ways that kids can understand (disability, adoption, breastfeeding, and I hear that the South African version has a muppet with AIDS for all the kids over there with AIDS to relate to).
Yes, it is American, but it's not going to change kids' pronounciation if they hear things said differently the rest of the time.
I once read a thread on STFU Parents where a woman took exception to there being an Indian woman on Seasame Street having a nose ring, which for some reason they thought was a terrible influence on children. You can't please all of the people all of the time.