I know I'm the odd ball out but I would want to lose my sight, here's my logic. Growing up I've always had a hard time seeing even with glasses I don't see 100%. So what I did is I use to go around my house with my eyes closed, I was training my other sences to take over if I ever lost my sight completely. My earing has improved to the fact I can here a dogs whistle. My taste and smell has increased (and sometimes I regret it.) My sence of touch has also become more refined. So if I was able to loose my sight I am still able to operate in a normal (semi) way. By loosing one of your sences your remaining 4 sences will increase to compensate for the loss of the one.
Zelph that seems to be the long route. For me it would be easy to give up smell, in fact sometimes you are better off not having it anyway. I mean of the five, smell is less critical - it is like losing the CD player, but at least having the monitor CPU, keyboard and mouse. In other words - you will rarely need assistance to get by from day to day.
I think I would choose taste. Although it would be so boring to eat food without being able to taste it, I don't think I could bear to live without, sight, hearing, touch and smell. If I lost my sense of taste, I believe that it would be so much easier for me to maintain my current weight. But on the downside, I would get food poisoning almost all the time!
Smell, its not even close.
Sight, hearing, and touch are all majorly disabling things to lose, so they're out of the running. Yes, you can compensate for them, but having to adapt to fill the hole left by something shows just how important it was in the first place.
Between the sense of taste and the sense of smell, I get MUCH more enjoyment out of the former, not least because I'm a pretty darn good cook.
P.S. We have a lot more than five senses, and several of them are quite important. For instance, try walking across a room some time without your equilibrioception, your sense of balance.
Edited: daishain on 11th Nov, 2017 - 1:14am
I am a bad sad case with my loss of taste and loss of smell I am down to three senses. With strong hands I am not good at delicate touches, my eyesight is going bad and my military service has left me with at least 25% hearing loss in both ears. SO I guess you can say I am living with the loss of taste and smell.