I love Jack, Wilf and Rory.
I prefer Jack on Torchwood to be honest but I still like the character in Doctor Who, he is just toned down a lot.
Wilf is amazing, no explanation needed. Plus he is Donnas grandfather.
Rory is the only thing that got me through Matt Smiths run of the show. Really really good actor, great character and was just good to watch. I outright disliked Amy until Rory started travelling with her and the Doctor actually.