Actually if you guys follow Jedi lore, long before they weilded light sabers they used steel sword powered by their force, so in reality you should consider an Old jedi vs the witcher, or else you should also consider witcher being like boba fet, weilding guns and stuff like that.

so this is the Final Verdict on who would win:

-- If considered ONLY the sword skills, the witcher would win. the witcher is a swordmaster killing machine.
-- if considered ONLY the magic skills, the jedi would win. because witcher signs are a joke compared to jedi force powers.

so i say that the fight can go evenly depending on what tactics are used. yeap i guess thats it. environment is also part of the equation, consider a place where jedi cannot freely use their powers without harming themselves -- i.e. tight spots, so i guess that pretty much sums it up.

The Witcher and The Jedi have 50% chance of loosing and wining. a draw perhaps, with both dying or surrendering.
please study jedi lore to know what are the mind control abilities, they are on par with axii, and cannot influence complex people like the witcher.

Dude, that mind control works over on lesser minded mostly and Geralt is not lesser minded than a jedi... And one more thing, Geralt can mind control too and not exclusively on lesser minded.

+1 rep for knowing the lore.

Talking about rep, how do you give it? Is it the green circle with plus? If it is that one i use it from time to time but don't see people i use it on's rep go up, someone has to get "plus"ed several times to gain one rep?

There is a thread answering exactly that question currently being discussed in the general discussion forum of gog.com :)
Here is a direct link: http://www.gog.com/en/forum/general/what_is_rep

Jamie's strong, but he doesn't have the speed of Geralt. Even at his finest, Jamie was known for being a towering and inspiring man. He takes battle seriously, but he would never be fast enough for a Witcher. It's a shame we never got to see him fight at his finest.
Triss. She's part of a gigantic conspiracy of sorceresses and has traveled over the entire world into many an adventure. She has he weak sides, yes, but the fact she can teleport to anywhere is a good consolation.
That's a tough one, honestly. I'd say Letho merely because of his powers. Were it simply sword to sword, it'd be Gregor. His nickname is after a beat.
Tyrion sucks at fighting. He's fought once, and that was merely out of duty. Sure, he killed a few, but had he not the people rallying behind him it would be the end of it. Zoltan's got military experience and can handle himself in a fight. I still love Tyrion though.
Now this is most definitely an even match-up. I know it seems like I'm favoring TW2 a lot here, but I still have to go with Iorveth because he does not fuck around. Legolas has his niceties, but Iorveth is a renowned killer of women and children to get what he wants. Not as wise as Legolas, but more brutal.

This isn't the most even match-up.

Against a lower level jedi (a "padawan" if you must) Geralt would probably be able to keep up.

But a higher-level jedi can typically multiply their speed by several times, see several seconds into the future at will, and lift objects weighing several hundreds of pounds into the air.

And there is no real upper limit to the power of the force, we've seen characters make stars go supernova, force push a black hole, create a giant force storm that can easily destroy an entire fleet, controlling many thousands of minds on a galactic scale, etc.

I think a fair question would be who would win in a hand-to-hand fight. But I'm biased, 'cause I'll be rooting for the witchers!

Uh... On second thought, I withdraw my last statement! Planetary telekinesis PWNS all!