W&N paints are what I use and I have no complaints. They also seem to have the largest selection of colors.
Strangely, I've found "Transparent White" to be a nice little weapon to add to the arsenal for subtle streaking and fading effects.
For thinner - Mona Lisa Odorless Thinner. The stuff is so mild you can put it on top of unsealed MM enamels (once they're dry, of course), scrub it around with a brush, and it doesn't phase the enamels beneath. Also flows exceptionally well.
On the Bench: 1/32 Trumpeter P-47 | 1/32 Hasegawa Bf 109G | 1/144 Eduard MiG-21MF x2
On Deck: 1/350 HMS Dreadnought
Blog/Completed Builds: doogsmodels.com