[esaias]

RME's are rock solid cards. Have had HDSP9652 for couple years now and 0 (ZERO!) problems. I've had Motu2408mkII, DIGI001, Korg 1212 and some cheap stuff and RME is just plain solid. I have lots of adat gear and I have never had a noisy loss of sync etc.
I can use 64 samples/buffer with 1.8ghz p4 :P (although very risky while recording but it works)

RME highly recommended.
EMU has good stuff.
M-Audio M-BOX has been praised too.
(Stay away from X-Fi etc. consumer products, go for more pro gear, it is worth it)

-Tomi