Mace Tulio said:
I've always wondered what it would be like living without the feeling of touch. You'd certainly have a high pain threshold.
The downside being that you could leave your hand on a hot stove and not realize...well until you smelt it
I'd go for taste; hearing, sight and touch are all obviously useful, but smell adds a quality to things that the others just can't. I think smell is the most under-appreciated sense, but while there are bad smells, good smells bring back the strongest memories.