DPS garen vs. tank garen
 

which one is better, or is it all situational? My friends suggested a 100% crit build, but I didn't think that that was good. Is crit a good way to build DPS garen, or should he just never be built DPS?

People tend to say that tank garen IS dps garen and the reason in simple you want to get in there and judgement the hell out of everyone and live through it. Unless you are tanky you are likely to get burned down half way through your judgement duration as your defensive thingy in and of it self is not enough (mid-late game at least). But because you are beefy it's simple math (especially for lower HP targets) they will loose more HP (at least relative to max HP) than you will and then his team comes in. Tank Garen does far better since he lives longer to wreck havoc and execute his ultimate for a kill. I have often seen DPS like Garens fire ultimate too soon because they are forced to do so before dying them selves which often leads to silly feeds.

what about a hybrid build, with one or two attack items and the rest tank?

You will have to ask the experts on that and I would advice to at least look at the plethora of guides that are out there first so you are better dressed to evaluate whatever input you might get.
I have played Garen very little and would never dream of doing it again because besides his KS ultimate he is so boring =P

garen's abilities do so much base damage that he doesn't need any damage or crit items. What he needs is a massive amount of armor/mr/health to stay alive long enough to silence spin and ult people.
Ghostblade is still a nice item on him tho, and that + atma's are usually the only non-tank items I get if I don't need any more survivability

Main difference is:
Tank Garen: does the same damage as DPS Garen, just has waaayy more survivability.
DPS Garen: the Garen for players looking for a champion who requires skill to play, the most fun build imo, you will barely deal more damage than sunfire Garen AKA tank Garen, and have a lot less survivability

Out of the 11+ games I have played as dps Garen, I lost 1, almost all of these games had an opposing garen who went sunfires.
I ... pwned ... his ... butt...

Tank is the way to go.

Although I suggest getting Phage/Frozen Mallet to be able to slow them on your Q hit for judgement.

I like a hybrid build as long as my team already has a tank. I find going dorans, boots, sunfire, brutalizer, then IE or FoN to be pretty effective.

Noob question, what is IE or FoN?