Converting tapes to digital

Have lots of tapes I'd like to convert to digital files without too much hassle. My system is all analog- ARC D-90 tube amp and SP-12 pre, plus nice old Akai cassette deck, and a decent CD player. Mostly play digital files now from my PC through a Music Bridge which works very well and with great sound.

What equipment would best allow me to transfer cassettes to flac/wmv/mp3 etc?
You want the "line out" from your cassette deck into the sound card of your PC. You can get as nice a sound card as you wish. From there the sound card converts the analog input into digital. Depending on your software, you can process the file to remove tape hiss if you wish (or process in other ways) and the file can then be saved in whatever digital file format you desire. I use Adobe Audition software for my analog transfers but it is a bit pricey. There are a number of other lower priced programs and even some free open source ones that will at least do the basics for you.
Check out the EMU-0404.

I just saw a cassette to digital player in a catalogue I got. Can't remember who (crutchfiel, audio advisor or one of the computer warehouses).
It was $149, plugs into a usb on your pc, does auto reverse, and can convert to mp3. Look around, you'll find it.
Audacity is often-cited freeware with lots of features and
support in the forums( There's also a purchasable upgrade if required.
Very helpful to get the A-to-D conversion OUT of the computer box. Much of the RF noise that you'd otherwise spend time trying to edit out, can simply be avoided in the first place.

I suggest one of the USB audio interfaces from M-Audio, or Presonus's Inspire-1394.