I use Nikon SB-800s. I also have Nikon 900s and a 910 (and an SB-600), but I always reach for the 800s when I need a small flash. The 800s are crazy cheap if you can find them used, are slightly more powerful than their newer cousins and are smaller in form. I bought the first one new and over the years 6 more used. They all still work like new. You can find them in good shape on the bay for well under $100, sometimes half that if you are patient.
I don't think you can find a better bargain.
Also, Nikons work well with Pocket Wizard products, allowing me to pair my Nikon flashes with my Einstein E640 strobes and fire everything as if it was meant to work together.
I know the Chinese flashes are well liked and have a following - I'm not knocking them, I'm just not a fan.