I really enjoyed Playmates' version of the "Classic" cartoon series Turtles from a few years ago. They weren't dead-on representations of the series' designs, but I kind of liked that. The took the old designs and removed a little of the goofiness from them that gave them just a little bit of edge-- perfect for adult collectors who grew up with the series.
However, if you're more of a "purist" when it comes to your Turtles (as I am, but only when it comes to the original comic series-- the true Turtles, damnit!) then you'll more than likely be looking forward to getting you hands on these new Turtles figures from S.H. Figuarts.
They look like they jumped right out of the cartoons, and with Figuarts, you know you'll be getting an awesome figure full of "extras" like multiple heads, hands, accessories and great articulation.
Expect US pre-orders for these figures to pop up in the next few days. Price and release date, as of yet, is not confirmed, but I expect they'll be about $55-$65 each.
The first two figures to be released will be Leonardo and Donatello.
More details to come as they're announced.