Besides the chips, room keys, tickets, tokens, posters, "action figures", blackjack layouts and media passes, just some other boxing items I collect are:

Beer taps

The Tecate ones are nice - the glove separates from the heavy bag at the base:

Key chains:

Baseballs signed by boxers:

I have:

Tommy Morrison
Aaron Pryor
Hurricane Carter
Manny Pacquiao
Mike Tyson
Buster Douglas
Tommy Hearns

Let me know if you have anything I might want!!