I was a huge fan of both the original and FFNY and thankfully didn't get to play Icon
FFNY had quite possibly the deepest character customization options outside of a wrestling game. The tats, outfits, jewelry really gave a unique flare for your character, while the fighting style combination made for really unique characters (since the order in which you learned the style greatly mattered as well). FYI mine was Kickboxer-Street fighter-Martial Artist with LOTS of bling.
Vendetta was simply an over the top wrestling game (which i think was sorely needed, kinda like Blitz: The League was to football), written with the AKI engine that was used with many great wrestling games from the past. It was originally supposed to be a WCW game but the plans were scrapped when WWE purchased WCW, so they went with rappers instead.
And DMX was the definition of broken. I swear with my friends it soon became a game of "pick DMX first" since there were no mirror matches in Vendetta.
I swear he is up there in cheapness with such greats as Ivan Ooze. Almost EVERY single move he had either targeted the head, or was a head submission. Tap out win, every single time. Even Ivan Ooze would tap out.