What should I upgrade on my cross bike first?

Question

I just got a used cross bike and every thing seems alright to me, but I have a bit of extra cash and I feel like upgrading my bike. Nothing really bothers me that much besides the weight of it.

Surly Cross Check Frame + Fork

Kore flat bars (I won't be in any UCI races.. and I'm more comfortable with flats)

Shimano XT shifters, brakes, derailer

Shimano 105 hubs/casette laced to Mavic MA3s

Thomson Stem and Seatpost

Avid V-Brakes

Answer 1

You seem to have a decent setup, although you haven't listed your fork.  The best advice would be to just wait and replace parts as they break, which they will.  There is no need to replace items that you are happy with, and you will kick yourself down the road if you need a new crankset, but spent the money on a new cassette that you didn't really need. (or similar situation)

That being said, bar ends are the greatest accessory ever invented.  Ever.  I recommend the shortys.  Avoid anything with a point on it though, i've noticed that bar ends have a unique way of jabbing me in the kidneys during bad wrecks.

I also recommend mtbr.com for different product reviews and expansive bike forums.  I have posted that link in sources.  Happy riding!