Best in what way?

Best value for money?
Strongest construction?
Lightest weight?
Best mix of components?
Best warranty?
Best after-sales service?
Best looking?
Most comfortable?

These are all points you need to consider and I doubt the 'best' at anyone of these will necessairily be the 'best' at all the others.

I don't think you'll get a bad bike from any of the manufacturers you listed (or most other big names (or many small names)). You really need to try the bikes to see what you like about them - in my opinion, comfortable fit is probably the most important factor, and for that you must try them out.

Once you've narrowed it down to a few that you've tried and liked, or have specific questions on a bike or manufacturer, come back and ask us, and we'll happilly give our biased views

In the meantime go and give them a test ride and enjoy it

With regards to forks opinions are very mixed but Marzocchi seem highly regarded by most users. Rock Shox have very mixed reports, Manitou generally good, Fox pretty good. Have a look at www.bikemagic.com or www.mtbr.com for reviews on specific forks.

Richard