Ricardo Arona happens to be my favorite Pride fighter. I'm new to Pride, but he is my favorite so far. I enjoy his style. Any guy who has wins over Sakuraba and Silva in the same month or so is pretty darn good in my book. I like his entrance music too.
I'm in the process of downloading the Arona/Ninja fight, but it's not completed yet. That one looks like it has some bad blood in it just by looking at the introductions and stuff.
Arona/Silva, Arona/Sakuraba are both good fights. I don't know of many others.