I'm finally replacing my DFI Infinity MB which has been a problem since I bought it. I'm also upgrading other parts while I'm doing this, but I'm having a hard time chosing a new MB. I've already decided to buy an Intel Quad-Core so it needs to be socket LGA 775. I'm also buying a new video card card (probably a Gefore 9800 or something around that price range). This biggest problem I think I'll face is a space problem. I also have a sound card and a TV tuner card (both PCI). Then there's my CPU heatsink which is a Thermaltake blue orb (its big). I'd like a MB that doesn't have all these squished together and have room for expansion later on (like SLI) . I also don't want an economy board. I paid the price when I bought that DFI. Let me know what's worked for you guys and what I should stay away from or should look for. Thanks.

Specs:
OCZ Modstream 780W
Creative X-Fi Sound Card (PCI)
ATI TV Wonder (PCI)
New Video Card (PCI Ex. x16)
4GB RAM
2x SATA HD
Intel CPU LGA 775 socket

Edit: I also have a big case so size of MB isn't a problem

For beginners (and experienced too) I recommend you check out MWave's "Motherboard Bundles" Wizard. This is a great research tool as it allows you to pick a motherboard, then the Wizard will offer a big list of CPUs and RAM that MWave has already determined are compatible with that motherboard. Or, you can start with a CPU and the wizard will list a bunch of motherboards and RAM options that will support that CPU. This is a great research tool you can use even if you buy elsewhere (although their prices are fairly competitive once you factor in shipping - if you live in the US). However, if buying the full bundle, for only $9 more, MWave will mount the CPU and RAM on the motherboard AND test them. So not only do you know from the Wizard that your components work together, you know your specific parts will not be DOA - a nice warm fuzzy for only $9.