Bulbagarden

Well, my favorite Pokémon is Raichu. My favorite color is yellow, but Raichu is cooler than Pikachu, hence why I prefer its evolved form. Yellow being my favorite color also means I like a lot of Electric Pokémon.
The cutest Pokémon IMO is Eevee.
My favorite Eeveelution is Vaporeon, with Sylveon and Umbreon close behind.
My favorite Legendary Pokémon is Mewtwo, mostly thanks to its portrayal in the anime and the lore behind its creation.
Latios and Latias are close behind Mewtwo on my list.
My favorite starters are, in the order of introduction: Charmander, Cyndaquil, Treecko, Chimchar, Snivy/Oshawott (draw), Fennekin, and Popplio.
My favorite non-Generation I Pokémon is Lucario.
My favorite baby Pokémon is Riolu.
If you want to know more, just ask.

I got quite a few I like. Greninja, Hydreigon, Sceptile, Typhlosion, Lucario, Luxray, Hawlucha, Heliolisk, Latios, Silvally, Roserade, Froslass, Salamence, Gallade, Sylveon, Togedemaru, Glaceon, etc.

Is Lucario your most liked?

Not quite, but it's definitely in the Top 10, likely even in the Top 5. And, like I said above, it's my favorite Pokémon outside of the original 151.

I quite like Lucario. It shares my #2 spot with several others. My #1 is a bit obvious, I think.

Greninja, I presume?

Indeed it is. What's yours?