My favorites are massa Grischuna neutral and carma tropic.
I just recently completed a fondant test. I tried Duff's, Fondx, Fondarific, Satin Ice, Wilton, Massa Grischuna neutral, Massa Ticino Tropic and cocopan white chocolate. I have made MMF previously and found it to dry out easily, and wasn't thrilled with it, so I did not try it again. Also, too much work! For each tested, I looked at the color, the taste, and ease of use. Cocopan (white chocolate) was very yellow, and I did not test it further, saving it for when I needed a white chocolate fondant. It tastes good, just like white chocolate. Duff's was a definite Ivory, Tropic was very white, and the rest were very similar light ivory in color. Taste wise, I liked Duff's and fondarific which both tasted like vanilla tootsie rolls, but Grischuna was close behind. My husband and son liked the Grischuna the best, finding the first two too sweet. I found the Tropic to have a slight chemical taste at first, but it dissipated, and when I tasted it on the final cake, it was very nice and tasted great a dead heat with the Grischuna neutral. Satin Ice (both the white/vanilla and white/ buttercream varieties) and Wilton were plain horrible and tasted like chemicals. For ease of use, hands down the Grischuna and Tropic are the clear winners. They were very easy to work with, smoothing beautifully with a porcelain-like finish. Duff's tore easily and was sticky. Fondarific was very sticky and stuck to The Mat (which I highly recommend). FondX handled well and wasn't a bad flavor - slighly citrus but had a less smooth final surface. Satin Ice tended to dry quickly, creating the crocodile skin effect. I let them all sit overnight before cutting. They all cut similarly, although the tropic cut the cleanest. I did not test the wilton. I have used it in the past and it handles nicely, but tastes so bad, I wouldn't use it on a cake. I will save it for covering cake boards and making figurines.
Bottom line, The massa grischuna neutral and Massa Ticino tropic were both great. The tropic is bright white, the Grischuna Ivory, which would be the only main difference. (Massa grischuna makes a white type called Americana which I have not tried yet). There is a website called fromscratch.com (now beyond buttercream I believe) that did a fondant trial as well. My impression from that blog was that the Americana did not handle well. When I need to order more, it will most likely be the Grischuna neutral, although I might order the tropic if I needed a really white fondant.
Cost - I paid 64.00 for 10 lbs Satin Ice (6.40 a pound) + 5.44 CA sales tax = 6.94 per lb
61.97 for 13.5 oz Grischuna (4.65 a pound) plus 25.00 shipping = 6.50 per lb
79.99 for 15.4 lbs of Tropic (5.22 a pound) plus 15.00 shipping = 6.20 per lb
The two Massas are not available at your local store and need to be ordered online. The Grischuna is ordered through Albert Ulster imports. No tax, but delivery is about 25.00 Customer service is great, and I got it in 2 days. Tropic can be ordered from a number of suppliers, and shipping varies depending on how fast you want it. Again no tax, so costs are similar. I don't remember how much I paid for shipping, maybe 15.00, but took 2 weeks to get.
I'd rather be baking!