If price matters, lets not worry about the best. Pretty much any interface is much, much better than the tape versions in the earlier generation. So, they are not all about the same but they are all really nice. "Really nice" in this case means the quality of your mics, cables, pickups, etc. may be the place you want to spend more money to increase fidelity.
If you want 8 channels on a budget, I recommend going with a firewire or USB 8-12 channel mixer. The mixer part is nice for its own reasons (live, live practice, eq, etc) but the mixer variety is also cheaper than the dedicated audio interfaces for 8+ channels, in my experience. So, google, or check ebay, for Mackie, Behringer, Alesis (and other) firewire/usb mixers and you can get something for a couple hundred bucks (used). It is easy to gobble up channels with synths/drum machines, multiple mics etc., so having more is a good idea even if you only plan on using one or two initially.