4th Gen Chikorita or Cyndaquil?

So, I am restarting my Pokemon Soul Silver and can't decide between Chikorita or Cyndaquil! Help me decide! :)

I personally prefer Cyndaquil!

I say give Cyndaquil a try if you are torn between him and Chikorita. I picked Chikorita on my last playthrough of Soul Silver because I think this line is the most pleasing to the eye to have as a pokemon following you in the overworld. It is cute, but it also takes the most work to raise. Chikorita has a type disadvantage in the first gyms against the flying and bug pokemon of Falkner and Bugsy. The matchups just get harder and harder as the story progresses, since you have ice, steel, dragon and ghost gyms coming up, and Team Rocket's poison pokemon. Even just walking through the world can use up a lot of potions and healing from the early route flying pokemon, the zubats in caves, crossing the waters and encountering poison moves from countless tentacool to finding your way through the ice path. You'll have to have other strong pokemon on hand to support your Meganium and cover her weaknesses since she doesn't have many coverage moves. Chikorita is definitely for the brave.

If you just really love Chikorita for its design and personality, and don't mind doing some grinding then you should go for it. But if you want to keep it a more casual playthrough then Cyndaquil is the fastest and has the most attacking power and doesn't have any gyms that its typing is weak against. It also learns a very strong move in Eruption and can also always land against the evasion tactics of Clair's Kingdra with swift. I say get Cyndaquil or Totadile to play it safe, and if you want to test run a pure grass pokemon in Johto then add a Bellossom on your team, its also very cute. If you like it then maybe use Chikorita next time.

I would choose Cyndaquil over Chikorita because there are better grass type Pokemon to find along the gameplay.

Chikorita in Johto is similar to Charmander in Kanto. Only for experienced players or those looking for a real challenge. Chikorita faces so many foes that have a Type advantage over it that unless you catch and raise a team that can cover for your Grass starter, you're better off getting Cyndaquil or Totodile as your starter. Sam(VisionofMilotic) said it best. For a Grass alternative, you got Vileplume/Belossom via Oddish line and Victreebel via Bellsprout line. Also give a look at Sunflora. May not be the strongest but it's an alternative.

After a long time of picking Chikorita in HGSS myself (entirely because I always pick the Grass types no matter what), I feel like, were I to start over again, I'd pick Cyndaquil. Mostly for the fun factor than anything else, and Typhlosion seems like it would have a much easier time with most of the Gym Leaders than Meganium would.

Pros to Meganium is that its defensive, so it isn't particularly super easy to knock out and iirc you can status your opponent but that's about it. It can't hit very hard so you have to work with what you have.

believe me, chikorita might be cute, but dont fall for its cuteness dont kill me, chikorita fans...
chikorita has many disadvantages in the game. if you wanna play strategically, use cyndaquil. and if you are like me, you might not even have to train any other pokemon (i literally won the pokemon league with typhlosion only)

Chikorita would be more of a challenge since it sets you at a disadvantage immediately against the first two gyms. Choosing Cyndaquil would allow you to easily go through the sprout tower.

I like both though and the last time I played I went with Chikorita.

i like cyndaquil more personally, plus you can have a more varied moveset than you could have if you start with chikorita. i like meganium a lot, but i find that no matter what game i have one in, i struggle trying to give it a fun moveset, but i never struggle like that with typhlosion. another good way to decide is by which one you're less familiar with, though. like if you like to use different pokemon to see how you like them, go with who you've used less.