I hate PrC's, so any time I see a PrC, rather than thinking about adding it to the campaign, I think about which of its abilities could be converted into feats.
With suitable prerequisities, I believe that there isn't much of anything which is a class ability which couldn't be a feat instead. Afterall, there is no rule which says that a feat has to be pure advantages. Taking a feat can carry both benifits and disadvantages along with it, as for just an easy example, a feat which cannot be used if the character is in heavy armor. A few abilities are abit more powerful than I want to introduce, and some are more powerful than single feats, but by and large I think this is a good system.
If you do this, I think you'll find that fighters are balanced as is. It solves all the problems. First, you will have more feats and more high level feats available than any one fighter will be able to take. Second, you won't have players tempted to go off into a PrC because not only do PrC's not exist, but they can take what they like from the PrC and convert thier fighter into that sort of character without the need for a PrC.
If that is not enough for you, I suggest slightly altering the fighter feat progression from every other level to 2 every 3 levels. That is to say, rather than feats at 1st, 2nd, 4th, 6th, 8th, make the feat progression bonus feats at 1st, 2nd, 4th, 5th, 7th, 8th. This ends up over the course of 20 levels giving only 4 more bonus feats, but gives a Fighter a much steadier progression without front loading the class. And lets face it, at high levels fighters are going to stop shining compared to spell casting classes at really high levels, so its possible (at least at levels about 10th) that they need a little bit of help. Provided you don't add too many broken feats to the fighters list (mostly in fighter's cases things that add non-circumstantial damage per attack and/or extra attacks per round) a few extra feats aren't going to be too much of a problem.
I haven't ran anything up to that high of level, because I like low level campaigns and feel that D20 progresses too fast (as a player I'd often find myself leveling up before even getting a chance to use the abilities I gained last level), but in my experience most fighter type characters end up taking a few levels of rogue and vica versa.