Don't be too concerned about what the "big name studios" use, that's a whole different league. If money is no object though, and you want to join the big boys, go for a Pro Tools HD system. That's 10K at a bare minimum.
Someone mentioned the UA Apollo. I have an Apollo Quad, and yes, that is a stellar sounding unit, if you don't mind shelling out $2500. Be forewarned though, those things, along with the UAD-2 DSP cards, cause a deadly disease named "UADPluginitus", for which there is no known cure, other than an empty bank account.
All jokes aside though, I concurr with all of the other suggestions given in this thread. Let me just add that I really like my Focusrite Saffire Pro 24DSP. It has excellent mic pre's and converters, flexable routing, solid drivers, dual headphone jacks, ADAT in, S/PDIF I/O, and an internal DSP chip that provides real-time reverb monitoring, as well monitoring/printing with compression and EQ on the inputs, should you need to do that. At a street price of $400, that's a pretty good value IMHO.
Apollo is my main interface for use with Sonar and Pro Tools and the Saffire linked up to it via S/PDIF.
JTW