£200 upgrade budget




I'm looking for some upgrades to my system and I have about £200 to spend. Currently I have:
-AMD A8-3870k with stock cooling
-Asrock A75m-hvs fm1 motherboard
-Cit 1011b midi black case
-Stock 500w PSU
-4gb G.Skill Ripjaws 1600mhz
-OCZ SATA II 60gb ssd
-Generic DVD drive
-External USB3.0 5400rpm 500gb HDD
-1080p acer monitor + a dell 1280x1024

I've got a few games (Skyrim, Assassin's Creed) but don't really mind about (not) maxing them out. Just wondering what would be the most worthwhile upgrade? :)
(I didnt know which sub-category to put it in so I put it in the hopefully :p most popular one)