I think it wouldn't take too much more screen time for me to flop a and b, but for right now they're sticking.

Jack...I'll try

a) Jack/Ianto in the sense of it being the best we've seen him in so far
b) Jack/Doctor/Rose because I still think he loves them best
c) Jack/Gwen, I even like Gwen these days, but this ship rubs me all the wrong ways
d) I think he loved Ianto after a fashion, but I also think Ianto is unfortunately right, he was a blip in time in Jack's life. I don't think thinking both of those things is very popular.
e) Owen, and sadly Donna. The why on the latter eludes me.