I always come back to T65 X-Wings, but (probably due to using them so much) I've actually had a lot of success with them, probably on about 2/3rds wins with treble T65 lists. My best success though was at an escalation tournament where I came 2nd, starting with Luke and Biggs at 60pts, then escalating with Wedge, Garven and finally Porkins when we got to 150.
However the ship I have tried the hardest with is Imperial Kath Scarlet. I've been using her with Slave 1, Extra Munitions, Ion Torpedoes, Guidance chips, Ion Bombs, Mangler Cannon and Rebel Captive, with only the EPT changing between games (so far used Snap Shot, Calculation and Adaptability). Took her to 2 small tournaments and won 3 out of 6 games pairing her with Kylo Ren (Upsilon) but it was always a struggle and when I lost it was usually badly. Tried her with Rexlar Brath in my last game and lost although my opponent was down to a single hit point on his last ship so couldn't have been closer, so I have a feeling Rexlar could become part of the mountain for a while!
For Scum its the Kihraxz, specifically Talonbane, but I haven't used them much yet so it's more of a small hill than a mountain at the stage. The YV666 is another one I haven't got the best out of yet.

