A few suggestions to get you started...
- Cyclops: strange thing on top of head
- Storm Crow: oddly small hands
- Locust: ideal crotch-height targeting
- Timberwolf: popular with masses, despite obvious flaws
- Pretty Baby: worst Hero ever
- UrbanMech: head swivels 360 degrees when possessed by demons
- Atlas: just keeps coming at you, regardless
- Vindicator: seems promising at first, but proves hugely disappointing in the end