The Winnersh Racer that's a tough one as it depends on your bike and what you want to carry. Personally I like the Oxford Lifetime luggage and the Kriega US bags. I use an Oxford X20 QR tankbag and Oxford Aqua50 rolltop bag on the Crosstourer and Kriega US30 and US20 stacked on the Fireblade. I also have a useful Oxford waistbag XW3R to carry wallet, phone, drinks, spare visor etc. Generally you get what you pay for and while the Kriega stuff is pricey it's top quality and totally waterproof plus with various stacking combos you can carry up to 80litres. You can also use the US bags as a tank bag with an adapter harness. I'm not a fan of panniers, hard or soft, but others rave about them. Have a look at what takes your fancy and read some reviews. Also ask any other bikers you know for their recommendations too. There is so much choice out there!
And one tip - get some ROK straps to tie stuff down. Brilliant things, much better than bungees (although Kriega stuff has its own brilliant and secure mounting straps)