Being someone who is rather touch sensitive and tends to be bothered by soap on my hands or very minor injuries, I'd have to say I would choose to lose the ability to feel. Losing sight is also a close second, as without sight I could not judge someone by the outside, which is something many people do, unfortunately. My other senses are far too important to me. Music is what makes most my life, so without sound I probably wouldn't be able to go on. Taste is important as it lets me enjoy (or figure out if something's been poisoned either accidentally or on purpose) meals and the like. Smell... I love smelling anything good, be it a scented candle or a flower. Smell can also alert one to fires or poisonous gases and the like.
I'd also like to add that people who already have a loss of a sense (typically sight or sound) have heightened senses, and if I were to lose sight I could try and learn to find my way around with echolocation. That's right, click my tongue and listen carefully to see if the sound bounces off an object. ...Of course, I suppose this would be harder to master at my age, but you never know.