I completely disagree, despite the massive stealth rock weakness, I think it's a great typing. Fire/Flying only 3 weaknesses plus it resists annoying fight type moves, and is naturally immune to the all popular earthquake. Besides, Tyranitar is commonly referred to as the best pseudo legendary, despite the fact it has 6 weaknesses including a 4x weakness to fighting types and a 2x weakness to earthquake.
Sorry, that was a little off topic, . I would personally like to have mechanoid pokemon, maybe steel/fighting. Or perhaps a possessed mechanoid, Steel/Ghost with levitate (only one weakness - fire).