Unicron (Armada, Universe)

The personification of evil itself. The very essence of chaos and destruction.

Ratchet, Wheeljack & Perceptor (Universe/RTS/United)

The medic, engineer and scientist.

Hound (Henkei) with MGS-03 upgrade kit

The upgrade kit comes with 2 blasters that can combine to form a rifle, a rack to mount the blasters, Jerry cans for its jeep mode and rocket launchers for Ravage.

Hound with Ravage (Henkei)

Looks very much like his G1 version. One of my favourite pieces. He has a very "anime" style head.

Onslaught (Universe) with Headrobots Butcher upgrade

This figure is just spectacular! The accessories, the detailing, the articulation, lights and sound... Even without the upgrade parts it's already an awesome figure. This figure is a repaint of the Transformers Universe Hardhead figure which, by the way, is equally great. Adding the upgrade parts turns it into a Headmaster figure! It comes with 3 extra guns, 2 combat knives, a backpack and a headrobot. If you have the G1 Headmaster Hardhead figure, the upgrade parts are fully compatible as well.

Dragstrip (Universe)

Recolour of Autobots Mirage (Henkei).
If you recall, Dragstrip forms a limb of G1 Combiner Menasor (usually Right or Left arm). If only it had articulation like the current Henkei version. I pray to the 3rd party gods they'd make one.
Note: TFC has done Devastator -> Hercules and they're doing Superion -> Project Uranos. Defensor and Menasor next? Mmmm...

Optimus Prime (United UN-06)

With Infinity Warfare add-ons.

Updated - 6/11/12:
Riding Wreckgar & vehicle mode.

Another Optimus (Cybertron) - Leo Breaker / Ligerjack

Ooohh grandma! What sharp teeth you have!...
Damn Hasbro and their endless "clones"...