They're all pretty cool, adjusting for the fact WotC was using unusually less competent out of house editors through CD, and went in-house for CA and CV.
My homegame Dungeon Delver (rogue4/ranger4/delver2) was middling on the 3.5 update, but happy DD was used as the sole 3.5 Epic class translation
I thought about asking the DM to switch to scout8/delver2, but I've come to rely on my particular class mix and high reflex save for evasion, plus it's too much retcon.
Scout and Spellthief are the best new base classes though. Swashbuckler was not as well done as Scout by a longshot. The alternate caster classes, feh. Wiz and Sorc are enough.
I have a wizard/elemental savant in Living Greyhawk, and hope to get more use out of CA than just the PrC update. (lost another caster level to Daitek Funding! ;-) I've played ten levels with just PHB spells, and never missed any of the Tome and Blood spells I had access to. I might pick up a few CA spells. There are some nifty PrCs here.
My Roguelike 9 might cherry-pick a feat or two, but as a Dwarf and an archer, his first 3 feats (PB shot, precise shot, rapid shot) simply aren't replaceable by any builderbook feats.
I just made a new Fighter 1 who is making heavy use out of the Shield feats and Shocktrooper Tactical feat path in his level plan through 9. (ftr6/exotic weapon master 3)
My cleric 2 will slurp up all cleric spells in all these books
and might try to snag augment healing or other nifty feat from CD.
my cleric 4 will do likewise with spells, but has a feat path leading to picking up a little pious templar and holy liberator.
my ranger 4 was already on the polearm-feat path from complete warrior, grabbing combat reflexes to start, adding quickdraw, and Hold the Line is for 6th, and I might consider the Shield tactical feat that lets me step into the square of a downed ally, even out of turn. I can Quickdraw a wand of CLW (weaponlike object) and heal the
ally on my turn. The various new/reprint Ranger spells are also welcome.
So, I'm using a little bit of everything. I'll make a new level 1 Scout at some point,
possibly a Spellthief too.
And no, I have no characters following the bbn2/ftr2/rgr1/Prc2/PrC2/PrC2 formula,
why do you ask?