Find your niche.
I've never really considered legendaries within my favourite Pokémon list because I always ended up not using them in the games. Just a personal rule I set myself. I mean, without such a rule, my team would be pretty overpowered.
That being said, my favourite will always be Squirtle. That little tyke rocks the shades well. And he was rocking it before Ash's Krookodile made it cool. Not that it wasn't cool when Squirtle wore it.
I agree that Cradily and Tropius are pretty interesting Pokémon concept-wise, though! Take Cradily for example, with its fake eyes and the ominous real ones. Cradily's a lot like Kabuto in that sense, but with a more interesting typing. Tropius, on the other hand, provides you an infinite supply of fruit if you take good care of it. After all, Pokémon never die of old age. It flies, too, so it's a win-win situation. :D