These look awesome! I've asked for Boar and Shaman for Christmas, and mostly paid for the 2-Pack myself. I decided to pass on the Unmasked City Hunter because of the paint, though I do feel a tiny twinge of regret...
As for the rest, here's the Lost Preds in order of most wanted by me:
Stalker/Skull - This guy is perhaps the definitive Predator in that if you asked a non-fan what they pictured when thinking about the Predator, they'd probably think of him. He has the original mask and color scheme, plus the expanded weaponry of the later installments. In short, this guy is numero uno on my list, and will be especially cool as the "next step" of the evolution of the Classic Predator, from the unmasked Classic to the awesomely painted Series 3 masked and beyond...
Borg/Lost - Without a doubt, this guy has perhaps the coolest, most unique armor and color scheme of any Predator. In a future Predator film, they should definitely base the main Predator design on this guy. I can't wait to see him in three dimensions...
Ram/Warrior - I love the blue color scheme, and his helmet is really cool, too.
Snake/Shadow - In addition to his really cool hide-armor, he just has this feel about him that makes him stick out. His gear is simple yet effective, and his color pattern is pretty interesting.
Gort/Guardian - I must confess that I'm not crazy about the character like some people, but there's no denying that Gort is an incredibly cool and interesting design, and Gort is such a significant part of Predator fan-lore that you'd be crazy not to get him! I do wish they'd show us a full picture of the prototype already...
Brother Boar/Scout - I would agree with someone else's post that he seems like the most plain of the Predators, but his subdued yet complex markings and colors make a nice contrast with the rest of the clan. Plus, his mask is really cool, and I prefer it over his brother's, and the necklace he wears with the shape of his mask engraved on it is really interesting too. Also, Boar just wouldn't be complete without him...