The Epson V700 is tough to beat, Tiff works fine for me.
I second peter's recommendation. I purchased its cousin, the V750-M Pro and use the included Silverfast software to scan my 6x7 chromes and negs. It handles film very well. While the 750 may be out of your price range, the bundled software really makes it worth the extra, in my opinion.
Scanned images are saved as 16-bit TIFFs.
I'm currently awaiting the wet scanning kit from Aztek as I hear that method is able to pull out even more detail in deep shadows.
If you go with the V700, you may want to invest in VueScan - it offers a bit more flexibility and is capable of producing better scans than the included EpsonScan software.