If you hate stall, you'll love these two sets (UU):
Nasty Plot Crobat
Crobatman (Crobat) (M) @ Life Orb
EVs: 252 SpA / 4 SpD / 252 Spe
IVs: 0 Atk
- Nasty Plot
- Air Slash
- Giga Drain
- Heat Wave
Crobat's immunity to Toxic, and access to Nasty Plot and Giga Drain make it very threatening against stall teams. Crobat's base special attack stat is only 70, but it hits hard after a few Nasty Plot boosts, especially when you add Life Orb. It will be easy to setup on passive Pokémon, as they can't badly poison it. Air Slash is for STAB, and is a good way to inflict hax on your opponent (or not). Giga Drain counters Unaware walls like Quagsire and Pyukumku, and is useful for restoring HP, especially against Blissey, which is a huge annoyance to this Crobat. Because of Blissey's massive HP stat, a Life Orb +6 Giga Drain will restore 35 - 41.3% of its maximum HP, which is more damage than Seismic Toss. Heat Wave hits steel types like Registeel, Scizor, and Mega Aggron for super effective damage. Infiltrator allows Crobat to bypass Substitute.
Taunt/Roost + Offensive Pivot Crobat
Crobatgirl (Crobat) (F) @ Flyinium Z
EVs: 252 Atk / 4 Def / 252 Spe
- Brave Bird
A less gimmicky set that can shut down stall teams due to the Taunt + Roost combo and Crobat's toxic immunity. Taunt cripples passive Pokémon that rely on status moves, such as Blissey, Suicune, etc. and makes them unable to recover. Roost restores 50% of Crobat's maximum HP, allowing it to recover from Stealth Rock damage, and switch into attacks more often. Brave Bird is for STAB and hits exceptionally hard when paired with Flyinium-Z. Sky Plate can be used if you already have a Z-move user. U-Turn allows Crobat to switch out while dealing damage, letting it act as an offensive pivot and gain momentum. Infiltrator allows Crobat to hit Substitute Suicune and Kyurem.
Watch out for Mega Aerodactyl, as it can be found on stall teams, and outspeeds and OHKOs Crobat. Also, you should probably use these sets in UU rather than OU (yk, Heatran).