Witch song do I start????

[SlowPokemon]

Some songs that I think are pretty awesome to start with, Pokemon-wise, are N's Farewell from Pokemon Black and White, as well as my own Musical Hall and Route 4 arrangements which are on the site. I only recommend those two that I arrange because I like to think mine are fairly easy, yet accurate.

Also Azalea Town from GS is good... Look at anything by DekuTrombonist, particularly his Route 47 if you're looking for Pokemon.

Fluffy Bluff Galaxy and Chompworks Galaxy from Super Mario Galaxy 2 are relatively easy and sound very good.

Sky Station from Super Mario Galaxy 2 if you're up for a challenge. Gusty Garden from SMG 1 as well. The sheets are practically impossible, but it's not that hard to pick and choose important parts so that you can create your own arrangement from it... sometimes you can even create more than one, it's pretty fun occasionally.

Hope this helped!

[Shadoninja]

calling the four giants isn't too bad

[DonValentino]

calling the four giants isn't too bad

True, I would also recommend that one! BTW, "Rocky Maridia" is not too hard.  Give it a try! 
It´s a beautiful song, but not too well-known, though.

[Oritendo]

Try playing the original SMB overworld and tell me how you do with it 

I agree.