Can anyone recommend one. I here people say that the toilets sold in Home improvement centers like Home Depot and Lowe's are not as good as ones you get from a plumbing supply store... any truth? What are good makes? Models?
And out of curiosity... I see some toilets say "Dual Flush" what does that mean? Is that for some wicked duces?

The toilets themselves are the same no matter where you buy them. Some big home stores like Home Depot may spec lower quality flush valves but I have not had any problems with them. Kohler and Mansfield are good brands but there are tones on the market. Whatever you do avoid buying the cheapest one you find. You should expect to pay about $200 for a good toilet that is already plumbed with valves.

Correct Sir, The Big Difference On What You Buy At Home Stores And Plumming Supply Stores Are The Valves, You'll See A lot More Plastic Parts With Lowe's And Homedepot, For The Money Its Not Going To Hurt To Buy From Lowe's, If You Have A Problem With The Product It Would Be A lot Easier On You When You Have To Take It Back,
I Really Don't Think You'll Notice The Diffence, Now You Installer Will,

Make sure you purchase the correct rough size for the space you have

Hmmm, they all will take crap from you, just a funny line. Some have
"polished" downspouts, and are suppose to be smoother on the inside to reduce the chance of anything getting caught, or hanging on the other type's imperfections. There may be some truth to this. One good feature besides what the other posts said is that the larger diameter downspouts will flush with more "authority" so to speak.