I really don't think dumb, dirt(And arguable iron..) deserve on the list with the rest of those names.
Thesaurus and illmac are going to have trouble rushing through the GP this year, I def. think arcane and dose and poRich seems to be bringing some heat he hasnt in a LONG time.
Dirt is..Not a good MC IMO. Funny cat, but bad rapper.
The fact is, to be a good musician and not write in a always funny and offensive way takes different skill that battle rapping doesen't promote.(I mean the lyracal side is comparable..but its' a completely different way)
Favourite battlers myself, atm..
Charron, Bender,saurus/ilmac,cane,soulkhan.
Not a top list,but people i like to hear.
Watch this before you write dirt off (or atleast his 3rd round 15:15)