Several years ago after a few cruises that stuck us with tablemates that ranged from boring to boorish, we swore off any line that didn't have some form of "show up when you want, get whatever kind of table you want" option in the main dining room. This was limiting for some period until most of the lines caught up with the idea that not everyone likes to be randomly placed at a table with others. Plus, we've always liked the idea of eating when the mood--and the day's activities--suited us. Oceania is very good about this, of course (it's their SOP in the main room), and we took several cruises with them. Now, I guess pretty much all the lines have this option in some form or other, which is very good.
As I've always said, we're not antisocial, and we've never failed to make friends aboard ship. With the "personal choice" availability in the main dining room, it's now easy to make a date with new friends to have dinner together on one or several nights.
We also like to try at least some of the speciality restaurants. Many of them are quite good.
We eat in the buffet at lunch more often than we should. The main dining room is usually a better choice for those of us who try not to overeat.
Mornings we get room service on port days and on sea days we usually do the buffet or the breakfast at one of the lounges for Elite pax on the lines where we qualify.