...right... well no one else is posting in here (yet, I hope), so I'll go ahead and start us off with some relatively unique Mew sets that I've seen or thought of.
Mew @ Choice Scarf
Jolly Nature
252 Atk / 4 SAtk / 252 Spe
- U-Turn
- Trick
- Outrage / Me First
- Explosion
It's pretty gimmicky for the most part, but when I saw it used against me, I thought it was pretty much the coolest Mew set ever. The set has several goals in mind, each of which is accomplished by a specific move: U-Turn scouts the opponent's team, Trick debilitates a wall like Blissey, or something else that needs to be able to choose its attacks, and Explosion (though perhaps less useful nowadays) sacrifices Mew to take down any specific non-Steel typed threat. Outrage (or Me First, if you're feeling particularly confidant about your ability to predict) is for revenging purposes; since it's the only attacking move on the set, a Dragon move is chosen for maximum coverage (and in Ubers, tons of stuff is weak to it anyway).
Mew @ Leftovers
Impish Nature
EVs: 252 HP / ? Def / ? SDef
- Dragon Tail / Roar
- Thunder Wave / Toxic / Will-O-Wisp
- Taunt / Magic Coat
- Heal Bell / Tailwind / Roost
Bulky utility/support/phazing Mew. Spread status with the first and second slots, use the third slot to protect yourself from Taunters and other statusers (Magic Coat + Roar is good if you're worried about Mischeivous Heart Pokemon, though Dragon Tail works either way). Third slot is for miscellaneous team support: Heal Bell can be used if your team lacks a cleric, new-and-improved Tailwind helps if your team overall lacks speed, hell, it can even be used to set up Trick Room if you want it to do that. Roost is an option for some recovery in that last slot if you're wanting it.
Mew @ Leftovers
Timid Nature
EVs: 252 HP / 4 Def / 252 Spd
- Block
- U-Turn
- Magic Coat / Taunt
- Hypnosis / Roost
LOLLL Block/Mean Look/Spider Web can't be Baton Passed anymore. What a shame. Well, the next closest thing is this set, which baits things like Tyranitar into switching into you, trapping them, then facing them to confront the ill-matched (for them) setup sweeper of your choice. Justice Heart Lucario, in particular, is a good choice to switch into the aforementioned example of Tyranitar.
Other sets I'm too lazy to do the full writeup for because they're kind of obvious:
- Pure SD: Swords Dance, Earthquake, Wild Bolt, Stone Edge / Dragon Claw / Sucker Punch
- Pure NP: Nasty Plot, Psycho Shock, Fire Blast, Earth Power / Vacuum Wave
- physical ResTalk: Rest, Sleep Talk, Bulk Up, Dragon Claw/Tail
- special ResTalk: Rest, Sleep Talk, Calm Mind, Dragon Pulse / Ice Beam
- something involving Super Fang
- SD or NP + Roost with 2 attacks
If anyone wants to correct my coverage on any of the sweeper sets, that's fine, as I kind of just threw these together. Coverage really isn't difficult for Mew at all since it can get perfect coverage with many different combinations. :D This was all that I could think of that Mew might use if it doesn't get banned to Ubers, but please feel free to keep coming up with stuff. I'm sure there're countless options with Mew's ridiculous movepool.