Currently I am watching Haibane Renmei, I always loved it but never watched to the end and I can't wait till I get to the last DVD cause it's really interesting (Don't anyone spoil it for me or I'll kill 5 kittens)

I also liked seemingly boring Animes like Somerdays Dreamers, other then these two Animes I don't know any other series like them, you know, peaceful, interesting, beautiful art and music etc, any recommendations?

Honey and Clover? It is a slice of life anime. My friends and I found it got boring after a while because its just about normal everyday life. But it has good music and is peaceful as you say.

Well, if your looking for a slice of life anime from the otaku perspective then I'd say give Genshiken a shot. It's funny in a boring sort of way, lol.

It is hard to understand what you mean but I am going to try anyways. Azamanga Diaoh is a really funny peaceful anime. Chobits gets thrown around a lot as being something super awesome, but it always kinda bored me. Love Hina is supposed to be good but I never got a chance to watch any of it.

You could try NieA Under 7; I believe it is from the same team as Haibane Renmei. I didn't personally enjoy it, but I think it might fit your criteria.

I think a lot of shoujo shows might also have elements that you're looking for; try something like Ultra Maniac and see if it's too girly for you.

Well, when it comes to "peaceful" anime, slice-of-life and comedy instantly pop up to mind. With that said, here are some of what I'm gonna recommend:

Comedy:
Full Metal Panic? Fumoffu
Bamboo Blade
Seto no Hanayome

Slice-of-life - has simple plots, and peaceful, some may feel boring.
Minami-ke
Lucky Star (first 4 episodes pretty boring though, but I like the ones after it)
[The above two are pretty funny and interesting as well] 

I haven't watch Haibane Renmei so I actually don't know what you are looking for, or if I understand what you mean by 'peaceful' correctly. If you mean something that has this surrealistic 'feel' to it then:
ef - a tale of memories

I'm not really looking for comical/funny style Anime's, ones that strictly fit HR's Genre, thanks for the suggestions though, I'm writing all of them down.

Now that I think of it, Ultra Maniac is pretty much straight magical-girl style; it probably wouldn't match what you want.

NieA, though, almost definitely.

you might want to try out:
ARIA, Yokohama Kaidashi Kikou (Yokohama Shopping Diary), Air, Sketchbook full color's, Asatte no Houkou, Hidamari Sketch, Hachimitsu to Clover (Honey & Clover), I My Me! Strawberyy Eggs! , Kamichu! - Kami-sama wa Chuugakusei, Koi Kaze, Kurogane Communication, La Corda D'Oro, Mahoraba, Mujin Wakusei Survive (Uninhabitated Planet Survive), Onegai Teacher, Onegai Twins, Petopeto-san, Ramune, Twin Spica, Windy Tales, Zettai Shounen

Oh! Definitely check out Figure 17 - Tsubasa & Hikaru. It's the only show that I know of with a double-length running time, which seems to give it a bit more breathing room.

I'll have to throw in a recommendation for Kaleido Star as well, just because I love it.