Yongnuo speedlite flash?

Which speedlite is yongnuo best in 2011, and would also be best for my Nikon D90. I like the SB 700, 800, 900, but find them very expensive. So thought i might just get the best yongnuo i can, any help is appreciated… Thanks all.

If you want TTL then there's the YN465 and 467.

If you are happy with manual flash (& tbh it's the best way to learn!) then you can't beat the YN560 imo. About the same spec (power & zoom wise) as the Nikon SB800 but at only around £40-50 a bargain!
To use off camera (the best way), get a set of RF602 triggers as well (about £18 a set).

Here's a strobist swim shoot I did using two YN560's & triggered with RF602's;

At 1/8 power or less the YN's kept up with at least 6fps shooting! No misfires at all.

I use Nikon speedlights as well (SB600's and SB800) and find the cheaper manual flashes as good as the Nikons. The RF602 is also more reliable than the (optically triggered) Nikon wireless system.

I use an SB800dx.

It is superb.