SenseOfTumour said:
Smell definately, as it also kills taste almost completely.
Would mean I could drink water instead of sugary drinks, and eat stuff like salads without wanting to throw up.
It would not mean you could drink water instead of sugary Drinks! I was born with anosmia (Inability to smell) and It means that I have real trouble tasting anything, to counter this, everything I eat must be very strong. I tend to cover everything I eat in a shitload of salt, or sugar (When I drink Pepsi, I have add extra sugar!) I know it's really bad for me but it's the only way I can get any experience, or pleasure from eating.
I know you didn't mean to offend, but please don't make assumptions about what it must be like, without at least doing some research. I'm fed up of seeing Anosmia trivialized by people who know nothing about it. It may not be the most serious sense to lose, but it still affects you life in a pretty big way:
Gas leak? I'd never notice
Milk makes me feel sick? Ask my Girlfriend to smell it for me to see if it's sour, normally it is, and I've drank loads of it.
Someone looks at me funny? Spend all day paranoid that I must smell really bad
Apples going mouldy in back of cupboard? I had no idea until my landlord said I'd be evicted if I didn't fix the smell.
Sorry to have gone on a rant, but it really gets to me, that people act like it'd be no big deal, and in your case even start listing the (false) positives.
EDIT:
Just for the record, I'm fine with people saying that they'd prefer to lose their sense of smell (I don't wanna kill the thread, and it probably is the least significant sense), just don't act like it'd be a cakewalk (Cos it's not) and don't invent false positives (Drinking water, easting salad, etc)