Some interesting comments on here. Of the PMs I remember, I think Steve a bit harsh on Wilson
He was certainly a wheeler dealer but I think he was perhaps a pragmatist rather than unprincipled. And that same judgement is something I would apply to Blair - more on which later.
Heath was, I think with a number of other PMs, unlucky. Too small a majority, and some global events did for him.
Callaghan inherited a difficult situation, and again was unlucky. Had he gone for an election in 78, I think he might have won.
Thatcher, as with Blair later, elected on a big majority, had power to change things. Still it took a combined initial affect of the SDP and then the Falklands War, which initially looked bad for her but winning made good, to get the 2nd election won. The win in 87 made her believe her hagiographers, and that was her downfall. Despite the narrative of Thatcherism, I think she too was another pragmatist.
Major inherited a divided party looking punch drunk, and maged to hold it together for the 92 election, which was probably the most disappointing for me because it felt as if Labour had snatched a last minute defeat.
Blair is as already noted a pragmatist, whose landslide allowed him and Brown to do lots of excellent things. I think you have to see them as a partnership because Brown was domestic focussed, and the deal between them gave him a lot more power than any other Chancellor in my lifetime. The war was a huge mistake, and didn't have a victory defined. Blair felt distracted by his place in history.
Both Major and Blair deserve credit for the Good Friday Agreenent
Brown had a similar hit that Heath did from global politics but I would argue did more to deal with it. Not sure if Steve's comment about lack of leadership derives solely from him not calling an early election but if so, I think it is argued against by both his Chancellorship, and his actions after the crash.
Cameron feels in many ways like another Wilson/Blair pragmatist but having a coalition, the ultimate in pragmatism, I think meant he underestimated the problems in his own party. His monument is Brexit which would be fine if it was what he had chosen.
May inherited an impossible situation for a pragmatist, and then wasn't pragmatic about it. The 2017 election was a huge mistake and one to borne in mind when considering if Callaghan or Brown should have called an early election.
Johnson is a disgrace to the office.