Help me pick a new receiver. Also a few ??'s

I'm in the market for a new receiver. I want to replace my older Yamaha receiver seeing as it doesn't have any hdmi ports, no ipod/usb connection, only 2 digital sounds ports, and other stuff I'd like. I've done some research and I think I've narrowed it down to two brands- Yamaha and Onkyo. If I could keep the price around $250-300, that would be great! Can anyone give me their real-world experience with these brands? BTW, I've been happy with my current Yamaha receiver.
Ok, now the questions- can someone explain HDMI pass-through? I've done some research online and I'm actually more confused than when I started. All I really want to be able to do is connect my stuff(ps3, satellite box, laptop) to my receiver and have one HDMI running to the TV. Will I still have to connect my optical cable(s)?