My XT came with the official Yamaha (acerbis) ones fitted. They look and feel pretty solid, and give me that extra piece of mind when filtering through tight gaps in traffic!
The other benefit is that they look really cool!

__________________
Racing
(a. & n.) from Race (v.t./i.)
The alchemy that turns base metals into heat, noise, power and motion.

I have just put black Suzuki DRZ400 all plastic hand gaurds on my XT660X. They look lovely, needed the bar end fittings changed to those bar end weights with the expanding rubber, but I had some spare ones in black anyway.
The are �35 new, got these secondhand of a mate of mine for much less.

cheers, strat.