Finally! This is a much more interesting tier to discuss.
Chesnaught for B+ as many have pointed out, this guy covers a lot of top threats, especially that sneaky mega tyranitar (still have no idea why the Dragon Dance is so barely used.... its part of its plan, so that its more effective...)
but I digress
Entei for B/B+ I personally think B+, because his ability to spread burns and completely put a stop to heatran as well a halfway decent offensive check for the zards makes him awesome. He is bulky, and has just the right moves (only 4, but thats all needs) to cover many, many threats. pseudo EdgeQuake, Sacred Fire, and awesome priority in extremespeed? So many different EV and item combinations means you can't peg him down immediately (even if you can predict his almost never changing move set). He also hits that crowded 100 speed tier, making him no slug for such an offensive tank.
Staraptor for B/B+ double bird while reserving your megastone for something else alongside his monstrous power levels makes it a crime to keep staraptor down.
Mega Absol for C/C+ his frailty is just too costly. Any strong neutral hit takes him out.
Chandelure, Darmanitan, Crawdaunt for B-/B They are all eclipsed by higher level threats (Chandy by Zard Y, Darmanitan by Zard X, Crawdaunt in a ways, by Bisharp) but have really deadly sets that can catch players unaware. Infiltrator Chandy catches a lot of substitutes (Kyu-B) off guard. Scarf Darmanitan punches huge holes, and partnered with Zard Y, scorch both spectrums with sun power. Crawdaunt's swords dance set is nasty, especially under the rain, though that's not necessary.
Dugtrio for B-/B is there a better physical trapper? Dude can take out a lot of high level threats, especially with his high speed, and with a focus sash, he can finish any 2KO's that need to be done.
Espeon for B-/B because baton pass shenanigans, and because his specs set his pretty damn hard.
Krookadile for C/C- Intimidate and knock off don't make this guy worth it, he's still too frail.
Machamp for B- He's outclassed by Conk as an AV user, but his more offensive approach via Dynamic Punch, Stone Edge, Knock Off, Ice Punch/Bullet Punch/Earthquake makes him more immediately threatening.
Ninetales for B- only other drought mon, and with WoW, Hypnosis, and overheat, it could provide decent support. It's also not slow, at 100 base speed it outspeeds most walls.
Tangrowth for B+ or whatever rank Slowbro gets bumped to because his AV set and natural physical bulk allow him to wall a huge amount of A/A+ pokemon and with good natural offensive stats and a very wide movepool, Tangrowth can retaliate on both sides of the spectrum, for good damage, and great healing in regenerator.
Trevenant for B- because Harvest lum rest with curse is a great stall mon, although its not very bulky
Thundurus-T for B/B+his massive special attack, double dance set and his scarf set catch many foes unaware, and dude, 145 special attack with that move pool? very under rated
*exhale* Dis mah tier. Says a lot about me though....