I went with the Hulk because he's bigger than any of the other figures and with cut wrist joints he has 2 more joints than most of the other figures. And unlike the Star Wars clone trooper, his hand doesn't have a 6 inch rifle permanently sculpted in his hand.
The sculpting is pretty cartoony, but that's to be expected. This is basically the budget 3 inch figure blown up to 12 inches. That means all the joints are cut joints. And almost impotent joint in the case of the hips since the articulation is impeded by the sculpted buttocks. You read that right, the sculpt of Hulk's caboose prevents the legs from moving more than a few centimeters. Fortunately that's just enough adjustment to improve a minor balance issue, but not much more.
Oh, and to save on plastic costs, the figure is hollow. 6 inch figures feel heavier than this figure.
My other issue is one of scale. The Titan figures are slightly shorter than other 12 inch lines. Check out how Hulk, one of the bigger characters in the Marvel universe, compares to the Marvel Legends Icon version of Dr Doom who should pale in size next to the Hulk.
Final verdict: good for the price if you want something low budget for kids that play rough or just to stand up somewhere. Otherwise they're less functional than a cheap Barbie doll. I might use Hulk for a background extra if I do a diorama, but that's it. I could be convinced to use these figures to team build a 12 inch team when other figures in the line aren't appealing to me.