My enjoyed moment: i attacked this lvl 35 guy's colony with massed bazookas and beetle tanks. i didnt think everyhing would be destroyed, but i ended up looting almost 500000 of each, and about 1000 xp.
Regret: srsly. in my first rival battle i 4got to train units and ended up looting 700 coins with 2 marines in a lvl 30 base.:)