The hardest part of getting Diamond is: - Destroying an AGR with Strela (or whatever its called in this game). It's rare enough for the AGR to show up, but to fire two rockets at it and survive? - Triple Kill with RPG I love using this in Nuketown. So many double kills.
http://youtube.com/watch?v=Pm1ytVdzfkI&search=baby%20got%20back%20sir%20mixalot Warcraft Got Back