I'm thinking of eventually making a monotype of every type, but for now, here's a surprisingly successful monobug team.
Forretress @ Leftovers
Sturdy / Bold
252 HP / 4 Sp.A / 252 Sp.D
-Stealth Rock
-Spikes
-Rapid Spin
-Volt Switch
One of the more effective leads that I've used. I try to set up rocks against other hazard setters, then spin away their hazards before Volt Switching out. If their lead is a threat, I just get out with Volt Switch. This has worked very well for me, though having my spinner at risk of being knocked to 1 so quickly has been somewhat of an issue. Sp.D investment keeps it from being absolutely murdered by special attackers, but Bold boosts stats more than Calm.
Scizor @ Choice Band
Technician / Adamant
252 HP / 252 Atk / 4 Spe
-Bullet Punch
-Bug Bite
-U-turn
-Pursuit
Pretty simple. Makes for a good pivot or simply a late game cleaner, as well as dealing with a lot of threats by virtue of being Steel-type and hitting Rock-types super effectively. Pursuit has seen limited use, though. Bug Bite gets up to 90 base power with Technician; after STAB it becomes a potent nuke.
Volcarona @ Chesto Berry
Swarm / Modest
4 HP / 252 SpA / 252 Spe
-Quiver Dance
-Fiery Dance
-Bug Buzz
-Rest
This is my favorite Gen V pokemon for a number of reasons, not the least of which is it's ability to rip entire teams to shreds after one Quiver Dance. Bug Buzz and Fiery Dance are an excellent coverage combo, and Volcarona's movepool is rather shallow, so I went with a ChestoRest set. Having the ability to clear status and recover to full health is invaluable, since you can set up in the face of common special walls after being hit with Toxic, then maul them at +4 or even higher after clearing your status. Even if they survive the first hit and Toxic you again, you've still got the ability to annihilate the next 3 pokemon provided one of them isn't ESpeed Dragonite, Talonflame, or Mega Pinsir.
Shuckle @ Leftovers
Sturdy / Impish
252 HP / 4 Def / 252 Sp.D
-Sticky Web
-Infestation
-Toxic
-Protect
This thing is evil. Set up Infestation so they can't switch out, Toxic them, and laugh as they try to batter past defensive stats exceeding 540. Infestation by itself is enough to kill a lot of Steel-types, so they are less of a problem than I originally thought. Sticky Web is good to set up between Protects as you stall something to death, and it helps the team avoid getting revenge killed.
Crustle @ Leftovers
Sturdy / Adamant
80 HP/ 252 Atk / 176 Spe
-Shell Smash
-X-Scissor
-Rock Tomb
-Earthquake
A physical setup sweeper. This team desperately needs a Talonflame counter, and this works splendidly. X-Scissor and Rock Tomb are a potent STAB combination, and EQ mauls Steel types. I went with Rock Tomb over Stone Edge or another more powerful move because it's reliable, and can open up an opportunity for the next guy to safely kill something. This was an excellent addition to the team; it can eviscerate teams with one turn to set up - and it always gets that turn. 80 HP puts this at 301 HP, enough to survive getting seismic tossed 3 times.
Yanmega @ Focus Sash
Speed Boost / Modest
204 HP / 252 Sp.A / 52 Spe
-Air Slash
-Bug Buzz
-Protect
-Hidden Power Fighting
I've had a moderate amount of success with this. Sash lets it take a hit and not die instantly from badtypingitis, Protect lets it not die again, allowing it to get to +2 Speed every time. It usually needs more than one turn to kill something, and it unfortunately lacks a way to boost stats other than Speed outside of Psych Up. Air Slash is reliable yet haxy, but is good STAB coverage. Bug Buzz is self-explanatory. HP Fighting kills Steels not named Aegislash (I have Shuckle and Volcarona for that), and Rocks that might come up, though honestly I don't think I've used it at all. Limited Speed investment because it has solid Speed already, and it will almost always be at +2 or more.