It'll never be like the first one again, unless of course they HD re-release it for some reason. It was probably the only Fable I played form start to finish 16 times. Mostly good, some evil, my favourite evil playthrough being an evil bugger with a chicken hat on, flipping off ladies and throwing up everywhere. It was just so much fun with excellent combat, hoarding, the legendary frying pan, everything. Of course you could beat the game using 1 of 2 spells, but it was still a choice which at the beginning actually had a small effect on the game.
Fable 2 was good, but it wasn't great. Everything new they tried to add was terrible, but what it never changed felt just right. It also has the most interesting DLC and the way it handled all the fun little gestures was good. There were parts where it sucked but it was still great to play. Of course the co-op wasn't bad, it was a start it just always made the henchman feel underpowered using low tier weapons, even with high stats. Magic was the only thing which worked. Adding the dog was a cute novelty.
I really dislike Fable 3 so much, there's just nothing left of what I loved. The menus aren't menus, hoarding all the food isn't possible any more, automatic health regeneration, the new magic system, micro DLC, mediocre gameplay, boring story and the god awful way of socalising with every NPC 1 by 1 was just a few things I dislike, yet I just can't bring myself to playing that game any more. It's just too much like hard work. I just don't like it, at all. It's just slower, the moral choices seem to be bleak and have no effect and the whole kingmaker thing gets redundant when you have enough gold to make the world pretty and save everyone.
tl;dr Fable 1 > Fable 2 > Fable 3