Feraligatr in Gen 2 . im sorry but theres just better water types to use in the game , meganium and typlhosion atleast can learn better moves overall and have more use cases
Even though Feraligatr faces the most competition out of these three, it's still by far the most usable of them simply because it has the most solid base and is only sidegraded by them at worst. Meanwhile, Meganium is not particularly worth the effort, and both Meganium and Typhlosion are heavily outclassed by their one competitor depending on the version.
Others have already talked about the sheer impracticality of getting Leech Seed onto your Meganium (female Chikorita, leveling Exeggcute to get Leech Seed, breeding, hatching, grinding the new Chikorita to keep pace, etc.), and mind you; Meganium is only the "least bad" Grass-type in Gold/Silver simply due to even worse competition, not that Meganium itself is actually worth the trouble. In Crystal, the early access to Leaf Stone makes Exeggcute itself a way better investment than simply being an egg parent to Chikorita. STAB Confusion off 125 SpAtk alone outstrips pretty much every offensive move any other Grass-type can do in this region, and Exeggutor still has Hypnosis and Leech Seed to overcome anything it can't beat down with brute force. What's that? You still insist on having Grass STAB on Eggy anyway? Then let's go back to the breeding thing. Not only is it far easier to get a female Exeggcute instead of female Chikorita, but you can also catch a Mega Drain Sunkern right away to breed that onto Exeggcute instead of having to train up a Exeggcute to get Leech Seed for Chikorita. So right off the bat, Crystal Exeggutor has the same moves you'd like to have on your Meganium (Reflect and Leech Seed) but offers additional sleep utility and most importantly raw firepower.
Typhlosion faces no such competition in Crystal as it is indeed the best general Fire-type in that game, but in Gold/Silver, the Magmar from Burned Tower pretty much
ECLIPSES Quilava and Typhlosion so much it's not even funny. Level 14-16 Magmar with STAB Fire Punch is just ludicrous, even outdamaging any Surf user you'd have access to by that point in the game. To further sweeten the deal, it can be taught the Thunder Punch TM immediately too (while Quilava has to evolve at level 36 before it can punch anything) and it gets
level 41 Flamethrower, an extremely appreciated power spike that leaves Typhlosion in the dust once more.
As for Feraligatr, the competition is fierce, but its combination of early availability (mostly relevant for stat experience), quick evolution level, well-rounded stats, and access to Ice Punch instead of merely "Icy Wind" already puts it ahead of the majority of Water-types in the game. There are only a handful of Water-types that can truly contest Feraligatr's all-rounder performance, and each of them have their own caveats that don't let them outclass Gatr as badly as Meganium & Typhlosion's competition do:
- Red Gyarados is the most standout example, thanks to its high catch level and superior physical prowess, but its weaker SpAtk and lack of Ice Punch means it puts up a substantially worse performance than Gatr where Water and Ice coverage matters (which is usually a lot of the endgame bossfights).
- Lapras definitely has the strongest in-game movepool of any Water-type in Johto, but it comes a bit underleveled compared to the other options available at a similar time (level 30 Gyarados or Repel-manipulated level 24 Surf encounters). You might also have to spend the Icy Wind TM on it anyway if level 36 Ice Beam for Clair is simply too far away for you, though at least you get STAB on it.
- Golduck is actually a really strong competitor; it has a stronger Surf and Ice Punch than Gatr and is faster to boot, which can make or break its Dragonite matchups. However, the lesser bulk means you don't want to trade blows with it unlike the aforementioned options & Feraligatr can better afford to do.
There are numerous other Waters left to cover, but I felt their disadvantages still made them less reliable than Feraligatr, such as Slowbro's poor Speed making it a Potion sink, certain Waters relying on potentially unavailable evolution methods like King's Rock trading & Gold/Silver Water Stone, or the useless Waters that are just not even worth mentioning lol. Even if Feraligatr is not the best Water-type in the game (this is EXTREMELY debatable btw), its standalone traits still make it one of the best Pokémon to use. Meanwhile, Meganium's status as "the best Grass-type in Gold/Silver" is basically an irrelevant niche, kinda like how no one gives a shit about say, "Crystal Weezing being the best Poison attacker in Johto".
Speaking of useless Water-types...
This thing has been featured in so many regional dexes, and in every single one, Goldeen/Seaking is unequivocally the worst Water encounter you can find for any given route. Mediocre stats, relatively late evolution level, GARBAGE level-up movepool...has there ever been a time where this thing is remotely close to a good choice, much less the best one? Seaking has pretty much no hope of contesting any late-game or even mid-game Water-type, so they try to make it available in several ways only for them to fail.
- Goldeen is one of the few Water-types you can get before Surf in the Hoenn games via Old Rod, but pretty much every single other Water-type available is either more immediately useful or just have better late-game prospects; even shitass Surskit at least has the decency to come with Water STAB.
- Even in games where they try and cheat out underleveled Seakings, it still falls completely flat. RBY lets you Super Rod for slightly underleveled Seakings? In some other routes you can Super Rod for Slowbros, Seadras, Poliwhirls, and Kinglers in the same fashion. Level 24 Seakings after obtaining Surf in GSC? Oh, you can also just Surf for level 24 Tentacruels, Golducks, Slowbros, Poliwhirls, Quagsires, etc.
- In Sun/Moon, you can fight Goldeens in Brooklet Hill to SOS chain for level 15 Seakings, which you can teach it the Scald TM to let it put in some solid work right away. This is probably the best Seaking has ever looked....until you realize that in that very same route, you can do the same SOS chaining for Magikarp to find equally underleveled
Gyaradoses, and Magikarps are infinitely easier to SOS chain since they can't even fight back. Seaking really cannot catch a break.
Seaking is treated as a mid-game Water-type across all its games, despite absolutely not having the stats to actually contend as one; it'd be funny if it weren't so pathetic....oh what the hell, I'll laugh anyway.
