Assassin's Creed II was my first

my most recent was Uncharted 3: Drakes Deceeption

If you know how many Blast Shards are in each area before moving on to the next one, then you shouldn't miss any. I know I did that, and I wasn't missing any from the first two islands before moving onto the third.

inFAMOUS was my first too! inFAMOUS 2 being my second, working on uncharted 3 right now.

Dude i really want to platinum this hopefully ill be getting R2 + R3 for christmas ;)

Resident Evil 5 was my first and it got me hooked on trophies.

The absolute hardest game to platinum IMO is Warhawk!

Also the Street Fighter 4 games are dam hard to plat. If you're no SF expert than its best not to try as its really frustrating.

My first platinum trophy is Demon Souls.

I've got six so far;
1) Terminator: Salvation
2) Assassins Creed II
3) God Of War
4) Prince Of Persia: The Forgotten Sands
5) God Of War III
6) God Of War II

I got three of them in quick succession; plat one game, move onto the next, plat it, move onto the next. That experience was very grueling, and for me, it somewhat ruined wanting to get platinum trophies in games. Getting Platinum trophies requires patience and dedication, your best bet is to stick with that one game until you platinum it, that's what I find hard. Barring, Terminator: Salvation, I had fun getting the Platinums for the remaining games, it's just the amount of time it usually requires to get a Platinum. It's been a while since my last Platinum, so I will have to start the quest....again.

My first plat was Uncharted Drake's Fortune. As far as plats that are still technically possible I'd say Lost Planet 2 is the hardest, but it might as well be impossible at this point. Aside from that one I'd say Gran Turismo 5 is the hardest.

My first and only platinum game is Demon's Souls. I loved the game so much that I wanted to platinum it.

1. Assassin's Creed II

2. WWE SmackDown vs Raw 2010

3. ICO

4. Uncharted 2: Among Thieves

And as soon as I finish both Uncharted: Drakes Fortune and Uncharted 3: Drakes Deception on Crushing I'll get Platinums.

Also to answer the question in the OP I went through my whole trophy list and GTA IV stuck out for me, I finished the game with both endings and still only had 1%, so I'd say thats probably one of the hardest games to Platinum.