Something that disappeared with the fateful </epicdrama server incident some time ago, was precisely this thread and its useful discussion.
This space will solely serve the purpose of discussing each Pokemon's placement in their respective tier lists; beg to differ, rant about how stupid a certain position of X Pokemon is (keep it flame free though), *insert discussion with common sense*.

We're starting with Smogon's Standards which are undoubtly the most accurate at the moment. Some stuff is a little off though, age destroyed some sense here and there, but hopefully with some observations and help from you guys we can make it loyal to the current metagame. It's a good start kick nonetheless.

UBER

This list englobes the Pokemon with the highest base stats, usually way off the rest of the Pokes's League. They have huge base stats, very wide movepols and overall great type combinations.

OU

This is the topmost tier for the standard metagame. It contains very strong Pokemon base stat wise, movepol wise and overall type combination too. They stand in the, sometimes, slim line between OverUsed and Uber.

BL

This is the most shaky and unstable Tier. It basically serves the purpose to include Pokemon which are underpowered for the OU tier, and at the same time, too strong for the UU. It stands as a middle-term category and is considered as 'fake' to many battlers.

UU

These Pokemon presented in this list are the most underpowered for the standard metagame. They have the lowest base stats, being Fully Evolved Pokemon, and a very tight movepol which makes them both predictable and underpowered. They require much more thought to them, but can be as useful when used in a team environment.

I'm surprised Clefable is UU. So many possibilites (not too shabby stats), makes it a pretty tough competitor.
Not to mention only one weakness.

Clefable is there probably because Snorlax and Co. do its work with just the same (actually, even better) effect. Clefable does greatly in an UU strictly environment though. I'll consider.

Wobbuffet how the ****** is he uber

Counter
Mirror Coat
Encore
Charm

190 base stat on HP.

... ^_^

wow thanks for clearin this up i never actually understood OU UU BL and stuff b4 now great job!

Is this completely finished. I'm not exactly sure. If its not, I'll check smogon and see what you are missing. This is great work Natbong. ^_^

i got knoked out by that in the battle tower

Havent we all...

its got heaps of Hp so if you get hit by a counter ur gone