I've only seen his fight with Oscar and it makes me when to see some other great performances by Quartey
Pretty much any of his fights between winning the title from Espana until prior to his draw w/ Lopez would be worth checking out then. His #1 best performance is probably vs. Vince Phillips, but he had other solid ones vs. Espana, Carr, & Tiger Jones. In general, his fights were usually briskly paced & entertaining.
Ike Quartey's fight against Crisanto Espana is a great fight to watch. Also his losing effort against Fernando Vargas has lots of action as well.
All of Ike's fights were fun to watch. Stylistically, he was never really in a dull fight and really was a hall of fame caliber guy that kind of shot himself in the foot by taking five years off in his prime. He was definitely better at 147 than 154.