There might be free ones, but they're probably not very good. I would deffinetly recommend Reason. Runs for about $500, but it's very good. It's more than just a sampler, it has a synth and sampler playback drumachine, it's is a studio in a box...
There is a new one comming out from Native Instruments, that is supposed to be the almighty of software samplers. I am looking forward to seeing what that can do.
I was very dissapointed with Halion. It has an amazing, intuitive, and a very easy to use interface, but the filters on it are absolutely horrible. They're weak, and the Reason filters puts them to shame.
Reason works very good with Cubase.
Reason allows the ReCycle files to be put into a module it has, DrRex, and apply filters etc to it.
The filters were created by the same programmers (halion and reason) so i don't think there's much to say there, plus both of those programs are put to shame when you run it through a true analog filter.
Nevertheless, I, being a Logic user, prefer the EXS-24....for VST users, check the EXSP-24, a VST version of the propietary software. You should also check Battery (native instruments), Kontakt (native) which i used the alpha version and seems killer.
Don't bother with Giga sampler or fruity, unless you just like to "play".......
Halion is a nifty, easy to use program, and the filters certainly don't sound like something on hardare samplers from emu, akai or yamaha: but if you're able to insert other plugins into the path, does it really matter? However, the Steinberg "feel" carries over to all their programs, and I just can't stand it.
So, as for the recommendation:
What app are you using to make music? It's best to go with the sampler most closely connected to your sequencer/recorder. Cubase? halion. Pro Tools? Samplecell. Logic? Exs.
Using something else, that doesn't offer a sampler from the same company?
The exs is pretty good, considering that it's compatible with a whole bunch of other software/hardware sample libraries, has a nice filter section, and puts all the nifty features into a real intuitive layout.
As for "free" samplers, I recall a s1000 emulation program, which read akai discs. Is it still around? Well, it was free, so it's worth investigating. My notoriously bad memory makes it impossible to remember the thing's name.
And: Cdxtract is certainly the neatest library conversion utility I've seen as of yet. It'll cover just about anything, including most hardware sampler cds (it'll mount, read and convert), plus exs, samplecell, giga... and alot that I'm forgetting.