On four numbers I am very happy with 2011 and 2018 and think that years 'to soon come' have a very good value (ie 2010 to 2020) Most other numbers I don't have a personal interest in but can see that some (but only a rare few) could have value.
On four letters, I think non dictionary, non brandables are, at this moment in time, quite useless. If anyone could sell names like TZRM.tv or YPWX.tv for anything above a dollar I would consider that the sale of the century!
My own favourite four letter names are MILK, SCOT, EINS, and RUFC
Ones I would love to own would include FILM.TV, TOWN.TV, ROME.TV, RENO.TV, PETS.TV etc. There are so many.