1: EAX is a dead tech; even Creative admits as much.
2: Sound quality is higher on most non-Creative cards (even the Titanium is sub-par, which keeps costs down at the expense of quality)
3: Auzentech cards fully support EAX, as they use the X-fi chipset (but are still hurt by Creatives (lack of) drivers).
4: ASUS supports EAX 1/2 through hardware, and emulates EAX5 (the most important) through its drivers, with basically the same compatability as Creatives method of wrapping EAX calls to OpenAL via Alchemy (the same games tend break with both implementations).
I take overall quality of the sound ahead of any extra effects personally, and aside from legacy titles, you won't see many (if any) EAX games produced at this point.
Basically, if EAX really matters, go with Auzentech, if only so-so, go ASUS, and if not at all, go HT Omega. Creatives cards are below the others in the quality of the output, and with their horrid driver support, I simply can not recommend any of their cards.
My recommendations:
Auzentech: Forte, Prelude
ASUS: Xonar DX, Xonar D2/D2X, Essence ST/STX
HT Omega: Striker, Claro
In the sub $100 range, both the Striker and DX are great buys, and moving up to the $150 range, very few cards can beat the D2/D2X or Prelude in terms of quality.