Any Rain team should always include a Spinner, as almost all of the good Spinners are Water or Steel, so they benefit. Rain offense falls apart too easily if you can't finish, which is why I prefer rain stall.
I'd post my team, but NOW I'm at my parent's house without my computer. I swear, when I get back to my computer at my apartment after break, I'll break down my Rain for you guys.
To get a jump start, I start with Politoed, and you guys can talk shit all day about how it may be bad, but realize this... with no Speed EVs, he's gonna be slower than Ninetails, so his Rain will counter the Sun. If you start off against a T-tar and the Sandstream prevails, then you know he isn't Scarfed. If you start off against Hippowdon, well, you already have the advantage, even if his ass has the Sand over your Rain. Boil Over if you have the advantage, switch if you'd take too much against the starter that you don't have an advantage over, and if you're pretty even or predict a switch, hell, Perish Song, so your opponent HAS to switch, giving you an opportunity to switch in your Pokemon to set up Toxic Spikes, Spikes, Stealth Rock, or set up for the sweep. It also does well to have a Wish user on a Perish Song rain team, since you can get the Wish passed as they switch on their 1 count.
In terms of Vaporeon, even though he has Hydration, since Water attacks do more damage in rain, I always run Water Absorb.
Best Spinners imo
Starmie vs Tentacruel
Starmie has speed and more offensive power, plus Natural Cure is awesome. My issue is that he's rather... frail, especially when you focus his EVs more on Speed and not defenses. I like Starmie because he can Thunder in the rain. I can also decide to make him physical or special defensive. But I also like Toxic Spikes, which Tentacruel has. His biggest problem is the Earthquake weakness. So long as I don't have to worry about hard physical hits, he's fine. And Rain Dish is AWESOME, holy shit. He can Spin and Toxic Spikes up, which leads me to selecting the next member of my team...
Nattorei vs Forretress
Both benefit from Rain's halving fire damage. If I run Tentacruel, I go with Nattorei, since Nattorei can take hits from both spectrums better than Forretress, who is heavily physical defensive. If I run Starmie, I go with Forry so I can have a spinner and a TSpikes user. Nattorei should have T-Wave for the Dragons he'll be switching in on after they DD Outrage. Forry is pretty worthless against so many Pokemon, as Spin/Hazard/Hazardormove/move limits him, especially when his movepool is BALLS. NOTE! Volt Change Forry is AWESOME. Switch in, then Volt Change out when you expect the Shanderaa. It hits a lot of Waters that switch in on him, and allows you to scout for their Shandy or Spinner ;)
I mix and match to see what works better. Sometimes I try Tentacruel and Skarmory. I've thought about Roserade, but since I've not much experience with her, I didn't want to mention her yet.
Anyway, once you set up TSpikes, two Perish Song Pokemon (Toed and Celebi) will slowly wear away your opponents' sanity. I've been playing my Rain Stall for a few weeks, and it's great. I just wish I had my computer here so I can go into MORE detail.
Edit: Zapdos was MADE for this gen's Rain. Holy fucking god. With T-Spikes out, and you switch on the Thunder(bolt), sub as they switch, then sub/roost while the Toxic wears them away, and then finish with a +1 never miss Thunder. SEXY.
Edit 2: Dragonite with Hurricane/Thunder/Draco Meteor/Super Power @ Scarf... rape