well, i would say that my favourite composer would have to be franz liszt ( as is obvious from my username). his compositions were very innovative (and unorthdox) at that time, and his piano music (or at least some of it) reqires a certiain degree of vituosity to play successfully. im not saying that that means he is a good composer, but it is something anyway.
some people (like chopin, whom i also revere) think his pieces are flamboyant, but i would say that is a matter of personal opinion. some of his gypsy tunes are also fantastic.
heres a liszt (forgive the lame pun!) of my favourite (piano) works by him (thought i like almost all of them):
hungarian rhapsodies nos 2, 6 and 12
paganini etudes nos 1,3 and 5
ballade no 1
transcendental etudes "feux follets", "wilde jagd" and "mazeppa"
all concert etudes ;)