Tanks.

Whoops, yeah I know he's AP. I played him before. Yeah, I was thinking about Malphite as well. I used to have Rammus and honestly, he's not my play style.

At this point, I'm pretty much between Shen/Garen/Malphite.
Shen because I can build him tanky with some AP and his skills are like the perfect kit. Garen because his shield has a passive that increases his armor/magic resist from the bonus amount he gets. Malphite because he has a good passive which would be pretty helpful in my opinion. When I play ADC against Malphite, it's pretty annoying when you deal like nothing early game.

From what you said on your OP, I suggest you not get garen and lean towards more of Malphite, Amuu, Rammus, Leona ideally I think the one that best fits your description is Dr.Mundo

If you play voli correctly he would suit you

But i think that someone you might find interesting is renekton, or mundo like Terrell said. They are both very fun to play, (Mundo can 1v1 anyone) And if played right, renekton can dominate top against most opponents. He has a high damage output, for early-mid game (Late game if you build damage as well) But he's still scary AF late game if he goes tank, especially with his ult.

Renekton is a very fun champ as well :P

OR you could try singed! Singed is...well singed. All you do is f*ck with people all game...Literally.

It mainly depends how you build with Garen, I would recommend a BC (black cleaver) and then just go mainly tanky items. I know it's out of the meta, but you can still go atma's if you're team lacks damage. Garen honestly has a very high amount of damage as long as you have some type of armor pen. BC should be a good item because it applies with your q, and each hit of your e. He also has sustain, which is great in lane. A very down side about Garen is he can be easily kited, which can be a serious problem laning phase. I would recommend buying more than one tank so you can pick for your team comp.
Malphite if a great choice, but if they are heavy AP he would suck. He has an amazing initiation, and completely shuts down the AD carry.
Shen is an all around great choice, he gives a shield and has his own (good for tanking).

I've tried Garen as off tank and it wasn't so bad, never played Malphite/Leona yet. Amumu is pretty OP but you need really good positioning to stun all 5 of them sometimes. I was considering Leona but when I see people with her, she's not as tanky as I thought she would be. Mundo has a lot of health regen but ignite really messes you over.

Never seen a full tank Renekton. Seems kind of interesting; he sounds better as a bruiser though. I have Singed as well, it's hard for me to go full tank, and yet have enough AP to kill with my flips and poison.

Yeah, he has a high damage output as well, but I'm just looking into him because He has a shield and a passive that raises your armor/magic resist pretty high in my opinion.

Ignite? You'll be jungling lol. I doubt minion monsters will ignite you . & Don't tell me that you'll die from ignite from enemy player when you're ganking because the only time ignite can even kill you or scuff you is when you're level 1-3. Again I think Dr. Mundo ideally fits your description.. and btw Garen is an offtank, a bruiser. You said you were looking for someone tanky that doesnt have any really damage output.

He knows what he's talking about. Malphite, Amumu, leona, or taric. Also depends on what lane you want. Malphite doesn't do much damage but he does a decent amount, scales off armor, and has a slow and a group knock up. Amumu has his tears + Rylah's for infinite slow and his ult for full team trap while dealing fairly nice damage. Leona is just a CC champ with a skill that'll bring up armor but no heal. Taric has a nice base AD (highest base AD in game i think) and that'll give damage, he can give armor to his ADC and to himself or deal damage with shatter, his ult will give his ADC more damage, and he has dazzle for stun AND heal.

Is Malphite good against AP?

Garen=High damage even without items? I mean like, high/low damage isn't my concern. I just want to be really tank.

LOL no, I mean like in team fights if they ignite me early on that'll let them kill me easily. Isn't that true? Mundo is like all about health/health regen.

Wtf teamfights? No you're insane by teamfights you'll be tanky enough to run circles around their ADC.

That's pretty much what I'm looking for! (: Do you mind telling me a good build? When I play mundo I tend to go Health Regen & a bunch of health.

Yeah sure, it's like you said I think you got the idea, you literally just stack HP you don't even need arm or mr unless they're fed or w/e. Just run warmogs, spirit visage, and alot of new junglers are starting to get iron locket as first items. Really the way you want to build him is to your own preference on how you want him to be. Some people like sunfire on him also while others rather the Randuims Omen, its up to you bro. If you feel insecure on your build look up mobafire builds or TSM builds.