I think what the OP is looking for is the development of TV shows with practically movie budgets. The quality of actors, directing, stories and special effects - just the whole package can be pretty impressive these days.
I think you are spot on with that.
I agree also of the list I mentioned that FlashForward is the least of these shows.
With regards to 24, I just never got into it, watched a couple episodes and just got bored!
Spartacus was one I was looking up yesterday, I think I will give that a go.
Edit: Heroes, same as Prison Break really, great beginning, then a rapid decline.
Will also take a peek at The Wire.