I would like the autocomplete list to use a most recently used (MRU) member selection algorithm that highlights the most recently used member in the list. As you know, Visual Studio already does this, and it saves a great deal of time.

This would be more than simply selecting the last used member after typing a dot (though that is a great start). It would also select the most recently used member for a given autocomplete character sequence. So if on an IEnumerable<T> I used FirstOrDefault() and then later used SingleOrDefault(), the next time I type "." on an IEnumerable<T> variable, it would highlight SingleOrDefault(). If I then type "F", it would highlight FirstOrDefault() instead of First(), since FirstOrDefault() would be the most recently used member for the character sequence ".F". Similar logic would apply to camel-case selections.