I'm not all that keen on Gina - she's just too much of a magnet for bad luck and misery! I much prefer Eileen, who basically has a decent heart but stands up for herself and bounces back when things get tough.
They should get rid of Billy, though. The actor's good, but it's just too much of the really dark, grim stuff. Lately when they've been focussing on the Mullans (and Lennie), and the Will and Robbie relationship, it's been much better.