People are saying too much. Get these 3 albums (click album covers for links, and proof that you can get each pretty ding-dang cheap.):
The Sugarplastic - Bang, The Earth Is RoundThis you will like. It is in the same vein as The New Pornographers, The Apples In Stereo, or The Shins. If you listen to or have ever listened XTC, this is like a cuter, less spastic version of them. Ben Eshbach is kind of this magical songwriter who combines the best elements of every Beatle. As you can see, you can get it pretty cheap, so goddam get it.
alaska! - Rescue Through TomahawkThis dark, rocktastic alternative will take steal your love away from the Dandy Warhols in a sniggity snap. I can't really think of anything else on your list that is really like them, but there are definately elements of a lot of stuff you say you like. "Real Is Your Control" and "The Light" are the definate standout tracks, download them, and if you like 'em, get the album.
Built To Spill - There's Nothing Wrong With LoveBasically this is a band you need to be listening to. They are heavy inspirations on a lot of stuff on your list, and they are also damn fantastic. All their earlier stuff is extremely terrific (their later stuff is good too, but not as good as the earlier albums), but this is the album I started on and it worked great for me, so I hope it'll work great for you.
KEEP IN MIND THAT ALL THREE OF THESE TOGETHER USED WILL COST YOU LESS THAN 10 DOLLARSSeriously, buy this stuff, enjoy. Happy Birthday.