Really want to play these games again but is it worth going through both or should I just pick one? 
 
What do you guys think?

Jak 2 is the best, but you should get both anyway. They're fun games ^^

Jak II is one of the hardest action games on the PS2, but if you've played through it before or simply feel up for the challenge, then sure, start with Jak II. You can always play Jak 3 after you've beaten it and are still left craving for more Jak.

Can't decide. Both are fucking terrific. 

Play both- they're amazing!

Both, but Jak 2 first. It's the best.

Jak 2 is better for sure. But Jak 3 does more of the same with some more powers and additions. But after both experiences Jak 2 was much better.

Personally, I prefer Jak 3. But you should play both, you can get them for like $5 now so it's not a big deal if you don't like them.

I have so many good memories of Jak 2. Such a great game.  
 
*Unpacks PS2*