well what about a garren, if he can silence before tryd pops his ult then its gg anyways?

Tryn ult breaks through CC now, doesn't it?

1v1 solomid, I'd say trist. Good harass, and can get an easy kill at 6.

Jax and Master Yi, tied for top, imo.

Depending on who gets fed more.

Garen is very team reliant and is a balanced champion. However, when built for DPS, he can't take enough damage to finish the kill against, for example, Jax or Yi. And same for a tank build, being unable to put out enough DPS to win. I feel this is because the only skill that scales with his stats is Judgement. All the others are flat bonuses.
Garen is best in a team fight, either soaking damage or dealing it, and then ulting on the carry or tank at the perfect moment.

In the scenario mentioned above, with who would be best 1v1 laning in those rules? I would say one of the ranged dps/casters who can harass extremely well and have escape mechanics.
Thus it would be somebody like Kennen or Ezreal, who would win in a 1v1 lane setup. Yes, Kennen. While he's squishy, I've yet to meet the Pantheon who can out-lane me when I'm Kennen. I HAVE met the Kennen who can outlane my Pantheon, however.

If we're talking about 1v1 ganking/dueling each other, not including lane phase, then it's going to be somebody like Pantheon, or Jax.

I was actually talking about this with a good group of players, Kennen is a pretty hard counter to Pantheon in lane because Panth gets ranged really hard by Shuriken and as long as you stay out of Shield Bash range you're never going to eat a Heartseeker.

Poppy

Trynd, DPS Malph, Jax, Shaco. Yi isn't strong 1v1 since he has no CC.

1v1 Invitational Laning Championships.
MegaZero's Tristana won. He beat Annie. (I believe Andy Dinh played Annie)
IMO Tristana with her range, rocket jump, explosive shot, and buster shot is the single strongest mid laner in the game. Although now there's Vladimir, and he looks to stand a chance at taking her title.

Nidalee Kayle Vladamir Heimerdinger and Shaco are some of the strongest 1v1 champs for obvious reasons