I'll try to say the same thing as above but with different wording:
The best share represents the highest difficulty share produced by you during the session cgminer has been running. If block difficulty is below the difficulty of that share then you have solved a block. Solo or pool mining makes no difference here.
So since difficulty is at 404, and I did 4.59M...??
Also, would it make a difference between pools? Like PPS vs PPLNS? Because I know PPLNS goes by how much you contributed to the block, right?