I've actually found that a bunch of my teams have glaring Ice weaknesses (My Leaf Green team of Blastoise, Persian, Nidoking, Electrode, Dragonite, and Exeggutor for example; or my White team of Samurott, Liepard, Eelektross, Golurk, Lilligant, and Archeops.) with three weak against Ice.
Probably my favorite teams were my Platinum team (Empoleon, Crobat, Dusknoir, Jolteon, Persian, and Flygon) or my XD Gale of Darkness team (Jolteon, Crobat, Persian, Dusclops, Walrein, and Flygon). And yes, there were a lot of similiarities between those two teams :P