Call me nuts, but I really enjoyed Salvation. I didn't care for T3 for a variety of reasons. I'm not a huge follower of the series (I've only seen the movies once each and didn't see the TV show) but I'd definitely be interested in T5 if it continued Salvation's story.
I actually agree completely. I think Salvation was the best of all the Terminator sequels and it was nice because you didn't even need to watch T2 or T3 to understand it. So I'm definitely interested in a sequel.