Tough question..
The "obvious" answer is Luis Suaréz. But, we have three very,very good strikers plus, Suaréz is a bit of a **** int 'e?
A year ago I would have said a&e. Always had a good game against us for Moyes Everton. He don't look all that anymore. A freshwater fish floundering in a stagnated pond (or swamp if you prefer)
Cahill from Chelsea? Again though, I think we've got some good players already in Demichelis and Nastasic.
I'd love to see Jack Rodwell and Ste Jovetic get fit and have a lengthy spell of gametime. Both have great potential.
I suppose in short, no fucker, happy to hear suggestions though!