out of curiosity, what would be considered a successful stint? what are the expectations?
In the minds of some, the minimum expectation is for us to win everything we enter. They believe that as the greatest footballing nation in the world we, with our team of world class players, shouldn't settle for anything less – winning every competition we enter is after all our god-given right.
In all seriousness though, I think the average football fan can stomach defeat – and England fans are used to the feeling after all – if the defeat is seen as being an honourable one.
As you mention, with the exception of our 1966 win the two best performances we've had came in 1990 and 1996, where we reached the semi-finals of the tournaments in question only to be knocked out on penalties after a hard-fought match against the eventual winners (a German side in both instances, but we'll gloss over that

). If our team has gone out there, given everything but has been beaten by the better side we might not exactly be overjoyed but at least we can take some pride in our performance.
What no one likes to see are gutless, inept performances by a team that doesn't really seem to care, led by a manager who appears seriously out of his depth at international level. We've had our fill of them, so as a minimum expectation can we have some committed, convincing displays from our supposed stars please, leading to us at least qualifying for and preferably progressing to the latter stages of the competitions we enter. Not too much to ask, surely?