I used to prefer the crimson, however, now I can surely say that I am corruption boi. I still think both the biomes are great, but there are some reasons why corruption became my favorite:
1. Thematic. I really, really like forests, and the fact that the corruption is just a dark version of the regular forest makes me like this biome a lot. Some people say the music theme doesn't fit it - I disagree. The corruption is, again, a corrupt version of the forest, so the fact that it's theme is just a distorted version of the forest theme really fits in, and makes it quite creepy when you think about it. Plus it's quite a bop, and something I like to listen to quite often.
2. Drops. I mostly play mage, so vilethorn and band of starpower are extremely helpful early on (no 1.4.1 on mobile yet, so I can't just craft a band using panic necklace and mana crystal; but even then, setting up a graveyard and a tinkerer's workshop this early on, and then tearing it down can be quite a hassle). Many people hate on shadow orb, but I like it due to it's simple design and the fact it's a beta version of wisp in a bottle. In hardmode, cursed flames are a pretty fun weapon, and I can get golden shower anyway by making an artificial crimson biome. Later in the game, I can use clinger staff, which I like because it gives me a way to apply cursed inferno whilst using weapons that are better than the cursed flames book at that stage of the game. Also, worm scarf is really nice for me since I really like using magic/celestial cuffs.
And lastly, even when considering the non-mage drops, I would prefer Ball o' hurt and Chain guillotines over their crimson counterparts.
(Also putrid scent, I thought it's aggro reduction did nothing in singleplayer but it does and it's dope)
3. Building materials. Crimson's Shadewood and crimstone bricks are cool and all, but I prefer ebonwood and ebonstone bricks because, again, they're just a corrupted version of the purity wood and bricks, which I really like.
4. Bosses and enemies. Crimson has a wider variety of enemies, but none of that matters when you can just box yourself in or run past them without much trouble, corruption enemies are made to be strong so early players cannot just run past the biome, which I think is fitting, evil biomes should act like a barrier to keep players at bay until they get strong enough. The enemies in the corruption are more simple, but I find them more fun and I like their designs more. Also, they're better for farming burgers and vitamins. And EoW is an extremely fun and juicy boss fight.