personally i never liked the XMB since the 4.30 update so i'd have to say modified 4.21 ITA as my fav firmware but the best i'd have to say is rebug firmware 4.65 - 4.78 cause the cobra and auto cex - dex convert etc. it's real helpful for people with no pc or usb or just too stupid to look it up, though rebug is buggy it's good, also i don't like the color red lol but it is good all that aside