Northern Downpour and Camisado are MUSTS for new fans, and let's throw in Sarah Smiles too.
Personally, I don't really like the music video for Girls/Girls/Boys. I just feel like they could have at least tried to make a real video, but that's just my opinion. I'm not saying that Brendon isn't hot or anything, I just kind of got bored watching it.
Oh man I love Panic! At The Disco. I've seen em live twice! Brendon has some voice. My favorite songs have to be Lying Is Most Fun..., Time To Dance, Behind The Sea, New Perspective... Gosh I could go on for days.
I'm digging the new album too, even though I do prefer older work with Ryan and Jon. Ryan just released two new demos, I recommend you check those out too.
In addition, check out Fall Out Boy too. They just toured with Panic! At The Disco. Patrick, Andy, Joe and Pete would love some more fans.