The Engadget ream did a nice review of the currently available Netflix streaming devices. The Xbox360, Roku Netflix Player, TiVo HD, Samsung BD-P2500 Blu-Ray Player and the LG BD300 Blu-Ray Player.
No easy winner in this bunch, but Engadget liked the Samsung for picture quality, the Xbox360 if you already have an Xbox360 or like gaming and the Roku for ease of use. For me, I'm considering getting a Blu-Ray player with Netflix and other online streaming built-in just to keep the number of boxes to a minimum - although I'd be even happier if SageTV worked out a deal to include the feature in their HD200 box to add alongside the coming-soon Hulu streaming feature. I think we'll see a lot more entries into this realm this year - CES had several coming-soon Netflix streaming players on display as well.
Check out the Netflix Streaming Hardware Roundup at Engadget