budget lcd or plasma: 720p good enough?

Again, depends on size and use. If you are not going to watch HD channels then you are definitely ok.

None of the networks broadcast in 1080P and there are no current plans to do so. 720p/1080i is fine. If you are going to have BlueRay 1080P would be beneficial.

I have a 50" 720p DLP display as a main TV, and a HT with 720p front projector on a 10 ft screen (see my system page). It's more than just "decent" IMO and I'm very happy with the resolution (even with the 10 ft dedicated theater), though maybe if I had spent any time with 1080p my expectations would be higher.

The pixel count is the most important. Not all TV's cover the full 1920 x 1080 which you need for full BD quality.

Plasma is way better than LCD ( I have both )

You seem to say this a lot when looking for equipment

budget is super tight....

Here is a video that might explain things for you :

http://www.youtube.com/watch?v=Z-JXfyvlPh0