I initially voted for Marcos because he was the best defender of the options available . . . . Mickey Gray couldn't tackle and wasn't really a left back (he was a tricky winger similar to Nicky Pickering, who sometimes got past people and sometimes didn't (in a 'pot luck' sort of way), Danny Rose is too small to be as affective as Marcos (and both were short term loan players) then I remembered (after reading some replies) that Hoolioooo was, and still is, Hoolioooo, so I changed my vote
I wont vote but Arca for my money. Gray was a great local lad who rightly got himself into the England set up (at a time when we had some good LB's). Arca was a better player and the fact he came back to the area and played (perhaps still plays?) for South Shields shows how much the club and people meant to him - locals have pretty much no choice which club they have in their heart (if I could have picked a more successful one maybe I'd have been happier...) but for an outsider to come in and adopt it as their own is something special. Plus when you signed him nufc.com had the rather wonderful heading "Mackems sign Arca Bandito"
The op does say at the SOL. Micky Grey played mostly at Roker. Some cracking overlapping runs with Allan Johnstone like.
Micky Gray spent more time at left back than Arca playing at the SOL fella. He played 5 years at Roker and 6 years at the SOL. Doesn't matter like cos Arca has won the vote anyway
Arca for me, just ahead of Rose, not relevant here, but I would have also liked to have seen Alonso and PVA together on our left flank.