Tsundere anime
 

Looking for an anime with a male tsundere character. (Cold hearted attitude, comes off as a jerk, warm inside)
I like animes where the two main characters start off not liking each other, but then their feelings change.
Animes like:
Inuyasha
Ranma 1/2
Kaze No Stigma
If you've seen those animes, you would know what I'm looking for. c:
I also like animes like Special A.
Where the two characters are friends, but the guy is in love with the girl, and the girl is unaware of her feelings towards him.

Try Tattoon Master and Hagure Yuusha no Estetica

Why don't you try Nodame Cantabile and Itazura na Kiss. I'm sure they'll meet your male tsundere requirements. So what do you think?

I would recommend:

Full Metal Panic
Haruhi Suzumiya
Maison Ikkoku (by the same author as Ranma 1/2 and Inuyasha)
The World God Only Knows (although the anime doesn't get deep enough into the story)

You might also try:

Chrome Shelled Regios
Familiar of Zero
Baka to Test
Soul Eater

Chiaki Shinichi, the male lead in Nodame Cantabile, is practically the poster-child for male tsundere characters.

Try Chihayafuru, though the romance is unresolved when the first season ends. We'll see where it goes in season two which should appear this winter or next spring. School Rumble has a classic example of this relationship between main characters Harima Kenji and Tsukamoto Tenma. In Kurenai, the titular character is the target of his childhood friend Yuuno's affections. If he realizes that, he doesn't acknowlege it.

In Cross Game both main characters are largely unaware of, or deny, their feelings for each other until nearly the end of the story. The roles are reversed in Yakushiji Ryoko no Kaiki Jikenbo where gorgeous police detective Ryoko has the hots for her male subordinate. He is either too dense, or too understandably cautious, to reciprocate. In Kurenai, the titular character is the target of his childhood friend Yuuno's affections. If he realizes that fact, he doesn't acknowlege it.

Syaoran from Cardcaptor Sakura

For your second request, try xxxHolic, and though it fulfils your requirement, it's not a shoujo. Also, Toradora, and to a certain degree, Kaichou wa Maid sama.

Kaichouwa Maid-Sama , if you liked Special A

I've already seen Itazure Na Kiss /:
and thanks, I'll give that show a try.

you can try Beelzebub. that show was pretty good. ;)

Dynamic tag cannot be rendered. (PrintableThread) Kunieda and Oga fight

Well how about MM! and Tora Dora