I've been having fun with a rain team; most notably, sweeping entire unprepared teams with Galvantula and (oddly enough) Moltres, and walling setup sweeprs with Quagsire.
Galvantula now has base 107 special attack and base 118 speed. Combine that with Thunder (which is now 91% accurate in neutral weather and never misses in Rain) and Bug Buzz, plup Giga Drain and HP Ice to kill threats like Gligar / Gliscor and Swampert / Seismitoad, and backed by a life orb it can really cause havok.
Moltres might be hindered STAB-wise by rain, but his new 100/100/95 defenses mean he can take most neutral and resisted hits fantastically in this meta. Furthermore he now has base 135 Special Attack and base 100 Speed (identical to Volcarona), and great dual stabs in Fire Blast and Hurricane. Fire Blast will hit almost anything Hurricane (or Air Slash outside Rain) doesn't remarkably well, even in rain, while HP Grass / Water / Fighting ravages the rock types that resist the combination.
Quagsire now has 105 / 95 / 75 defenses, which combined with its great typing, Recover, Stockpile and Unaware can pretty much stop any setup sweepers (especially physical ones) that aren't grass type, including massive threats with improved stats such as Bulk Up / Swords Dance Gallade and Dragon Dance Kingdra. It also has base 95 attack which means it can't be completely shut down by Taunt, especially with its awesome STAB moves in EQ and rain-boosted waterfall.