Flamestrike
Legend
I pretty much enjoyed every 3.x book except Tome of Battle and Magic of Incarnum.
Im with you on Incarunum, but ToB filled a niche for me. It gave martial types something to do other than just repeat the full attack action each turn. Instead of 'I attack' you got 'I'll strike the bad guy with Emerald razor strike' etc which is just a lot more fun and thematic.
It also allowed for combos, stances, parries and other counters, and the flavor was on point.
After playing a Warblade, I struggle going back to normal martials again. I just find them boring as hell.
I think that, like a lot of the supplements, if you ran a campaign just using ToB without Complete Warrior, or Incarum without Complete Psionics (or any of the other magic supplements), it would probably be ok.
The best way to 'save' 3.5 while keeping options open is to limit each PC to 'Core+1' for their PCs. It allows most of the bloat and options into your game without it getting out of hand, while stopping most of the truly insane builds out there, and allowing player choice. It also cuts down on the System mastery metagame that is the core of 3.5.
Even at a table of 5 players and a DM thats the 3 core rulebooks (which you should already know by heart) plus a maximum of 5 other books you need to know.
To make things easy on the pocket, make the player who wants to use the book, provide it.
I'd definitely still curb caster power a little in a 3.5 game I ran. Using 5E's spell progression for casters is the way to go for sure (more spells at low levels, but fewer higher level slots).
A rule I quite liked as well was the 'Rule of Three'. No PC can have levels in more than 3 classes (including PrC's). That also did a lot to even out the power curve among players, and keep the truly insane combos to a minimum.