You can find mespirt in :
Dimond
Pearl
Platinum
HeartGold
Soulsilver
Black 2
White 2
Pokemon Mysterdungeon Darkness/Time/ Sky (Maybe the new Mystery dungeon)
(You may be able to catch mespirt in the new games, Pokemon X and Y)
you go to the Pokemon league and a karate guy will give it to you after you beat the eliate 22 times
if the Pokemon was mesprit, you need to chase him. on the pokewatch click the things until you find the map. there will be an icon that looks like a bear's face. follow the face. mesprit will be in the grass
anywhere
You find it in the Galactic Headquarters after they capture Azelf, Uxie, and Mesprit.
it's in lake verity
your home lake
Mesprit & Cresselia (legendary)
In map 22 (Ground)
mesprit is at the descon wold and then it will be at verity lakefront and then it will start going around sihhoh in Pokemon platinum
You'll find The Lake Trio: Mesprit, Uxie and Azelf.
uxie azelf mesprit and palkia
mesprit is a legendary Pokemon and legendaries don't have gender However, In Pokemon Mystery Dungeons, Mesprit is considered a giirl.
You can find Palkia, Uxie, Mesprit, Azelf, Giratina, Cresselia, and Regigigas
go to all three lakes and you shall find all three
First you have to go to the lake closest to your home town. Use surf and go to the little 'island' in the middle. enter and you will see mesprit. Go talk to mesprit and it will automaticaly flee (don't worry, you and mesprit just start playing a game of... 'tag'). All you have to do is look for mesprit with the Pokemon tracker and battle it. It's best to have a Pokemon that knows mean eye so it cant escape.
in Pokemon pearl you can get palkia, giratina, azelf, mesprit and uxie. plus any tht u can migrate from other Pokemon games
it is mesprit