that's a no brainer

1 mainly because it's so much more cumbersome to play in general. That and the enemies take hundreds of bullets... each

Uncharted 1 by far. The enemies being bullet sponges back then didn't help much.
 
I think 2 is slightly more manageable since all the clunkiness of the first one was fixed. Don't get me wrong though, I liked the first uncharted very much.

uncharted 1. 
everyone took SO many bullets to kill. 
 
still a good game though.

Well when I played Uncharted on Normal it felt pretty hard, Uncharted 2 on Hard wasn't that bad, so I can't imagine the how hard the first is on crushing.

I still haven't gotten through Uncharted 1 and within a week, I am half way through Uncharted 2. 

" 1 mainly because it's so much more cumbersome to play in general. That and the enemies take hundreds of bullets... each "

You can activate tweaks via an exploit in Uncharted 2, and give yourself unlimited ammo and one shot kills. 
 
So yeah, not the first game.

I've finished Uncharted 2 on Crushing, and it felt fair, and I was enjoying it.
 
I've got to chapter 6 (or 8 I can't remember) on Uncharted 1 and I can't be fucked any more... it's not even unfair, it's just down right impossible.

I'm up to chapter 22 now in crushing and I have to say Uncharted 1 was a lot harder. The enemies were much more agressive and you had to keep moving from spot to spot. Here you can just pick them off behind some cover usually.

" I've finished Uncharted 2 on Crushing, and it felt fair, and I was enjoying it.  I've got to chapter 6 (or 8 I can't remember) on Uncharted 1 and I can't be fucked any more... it's not even unfair, it's just down right impossible. "

Drake's Fortune's Crushing was way harder mostly because it didn't control as well and, like other people have already said, the enemies took tons more bullets. Crushing in 2 was fun and just hard enough, in my opinion. 

" You can activate tweaks via an exploit in Uncharted 2, and give yourself unlimited ammo and one shot kills.   So yeah, not the first game. "

Uncharted 1 is a frustrating, semi-broken piece of shit on the higher difficulties.  Uncharted 2 is tough but incredibly fair.

uncharted 1 wins this one. Seeing how enemies are just sponge bullets and thats only for the normal difficulty. 

U1, no doubter. I still have not beaten it yet. :(

" 1 mainly because it's so much more cumbersome to play in general. That and the enemies take hundreds of bullets... each "

" uncharted 1. everyone took SO many bullets to kill.  still a good game though. "

I'd say the first is the hardest since I don't want to play it anymore.