Well, I'm currently testing a Rain-based Offense team, and it's doing *quite* well, even take down a Sandstorm team or two.
Although, I did have my first run-in with a Rain-Stall team, while I was using a Rain Team, and I have to admite, Rain Stall shuts Rain down pretty badly. It just can't do squat against anything else, especially other weathers.
Anyway, Rotom-W is doing great, and, oddly enough, so is Garchomp [Takes Electric attacks for Emploeon, Gyarados and Politoad, meanwhile, Emploeon takes Ice attacks all day]
I'm finding Gyarados somewhat underwelming [I'm using Resttalk], although boosted Waterfalls are nice, Dragon Tail has a nasty habit of missing. Agility Emploeon is... OK, but I'm using it for Ice Beam more, which is making me consider switching to a Water/Ice type, or maybe Starmie, or another supporter.
I'm yet to try either Genie in the Rain. Getting to those. I already have Rotom for the Thunders.