Handle as many ML's as you can get your hands on. Try to bring your hunting coat and gloves as well. When you figure out which ones feel the best. Narrow your list down to specifics.

My personal choice if I were investing today knowing what I know;
Thompson/Center Omega or Encore. I've hunted and shot both and own the bottom of the line Blue/Black Omega. Shoots very good. What I saved on stainless and the Encore I spent on Optics. Thompson Center service is one of the best companies I've ever delt with not only from firearms manufacturers but any company. Lifetime no questions asked warranty to the original owner.

Knight Elite or Extreme. These are very good shooting handling as well. Knight service is good. Lifetime warranty.

Savage 10ML. The Abrahms Tank of ML's. A real good shooter. Savage service is supposedly very good as well. 1 year warranty.

Brutus-Pedersoli Denali. Nice handling. Available from Cabela's. I don't know anything more about them.

Lots of info in this and other forums.

Also check out http://www.chuckhawks.com/index2h.muzzleloader.htm Randy Wakeman has done many evaluations on several ML's.