Pre-evos that you like more than their evos...

Pretty self-explanatory. I'm not talking about stats right now, just preference and coolness.

For me, I think Scyther>Scizor, Haunter>Gengar, Abra>Kadabra>Alakazam, umm...Charmeleon>Charizard, Growlithe>Arcanine, Porygon>Porygon2, Poliwag>Poliwhirl, Chansey>Blissey, Shellder>Cloyster, and Dratini>Dragonair>Dragonite.

I love all of them though, regardless of whether their pre-evo is cooler... =)

EDIT: Oh yeah, and I prefer Wartortle to Blastoise.

I like Wynaut better than Wobboffet

Scyther
Abra
Porygon
Cyndaquil

No, Poliwrath changes the least of all. Just add some weight to a Poliwhirl's arms and you're there.

I prefer Wartortle to Blastoise. (Also prefer it more than Squirtle)
Charmander > Charmeleon (although I like Charizard)
Mudkip
Torchic
Flaafy
Poliwag
....and probably more. xD

wynaut is cool like he said.

I thought I'd have more of these, but I don't have many.
Bayleef is the only one I can really think of. And the following I only prefer to their evolved forms because I like their looks better.

Magby
Smoochum
Whismur
Spoink
Metang

Ooh, Metang is a good one! I agree, along with spoink. Wynaut is cute but I like Wobuffet.

For some weird reason, I like Haunter more than Gengar, although it's only a slight difference of favoritism. It might be because I always felt that the anime's Haunter was cooler than its renditions of Gengar, but whatever.

I'm also fond of Rattata over Raticate (because the former is cuter, although I like them both), Ralts over Kirlia (although it's also Gardevoir over Ralts), Growlithe over Arcanine, Oddish over every other member of its family, Squirtle over every other member of its family, and Surskit over Masquerain. Only Surskit is explanable (other than the aforementioned Rattata), and that's because it's just better for an in-game team than its evolution.

In no particular order...

Grovyle > Sceptile
Sneasel > Manyula
Dragonair > Dragonite
Scyther > Scizor
Wartortle > Blastoise
Wooper > Quagsire
Metang > Metagross
Haunter > Gengar
Kadabra > Alakzam
Pidgeotto > Pidgeot
Meowth > Persian
Seadra > Kingdra
Lombre > Ludicolo
Nuzleaf > Shiftry (Shiftry's the ugliest Pokémon ever :P)
Wingull > Pelipper (PEEKO!)
Surskit > Masquerain
Vigoroth > Slaking (Eww Truant)

and my friend has Pikachu > Raichu

Grovyle > Sceptile Pidgeotto > Pidgeot Pikachu > Raichu Charmeleon > Charizard Taillow > Swellow Ponyta > Rapidash Doduo > Dodrio

Woops, I forgot Grovyle>Sceptile and Mudkip>Marshtomp. Oh yeah AND Wingull>Pelipper...there are so many... =)

Shegon>salamence(I love shegon.)
Charmander>charizard
Kirlia>Gardevior
All I can think of right now.

clefa is way cooler then clefairy or clefable

Charmeleon>Charizard
Poochyena>Mightyena
Dratini>Dragonite
Pikachu>Raichu
Meowth>Persian
Pidgeotto>Pidgeot
Those are mine that I could think of...

Let's see... I like:

Dragonair more than Dragonite

Charmeleon more than Charizard

Feebas more than Milotic

Ivysaur more than Venusaur

Wartortle more than Blastoise

Quilava more than Typhlosion

Magikarp more than Gyarados

Haunter more than Gengar

Zubat more than Golbat and Crobat

Trapinch more than Vibrava...

the list goes on

As much as I like the drinking Bird image they got with Porygon2, I like Porygon's crystal look better.

I also have a fondness for Kabuto, looking so mysterious and bugged eyed. Kabutops, just loses that mystique with its predator style.