There is no "best" line. Everyone will have different preferences, different favourites and different recommendations. When it comes to sinking lines for general angling, with lines of 8lb or less, I rarely look further than Maxima.
Following Jerry's recommendations i have found Pro Gold to be a reliable line and I find the 6.5Ib incarnation great for method feeder fishing. Also use Maxima - stronger than its rating which is why its diameter cannot match newer lines rated at similar BS.