A lot will also depend on the amount of space one has. Like Diane, N scale is just way too small. After years being in HO I can't believe that I was actually in N scale when I see some of the exhibits running. Makes the hair on my neck stand up.
If you want to see long trains run and don't have a lot od space, N scale is the way to go. The quality of todays locomotives is excellent.
If you are looking to build a highly detailed layout, and running long trains isn't important to you, HO scale is excellent. The availability of locomotives, rolling stock, buildings and vehicles is very good. I model the transition era and over the years have built up quite a collection of vehicles that are excellent for the transition era. I have seen many switching layouts built on shelves that have excellent details work and switching that can keep one busy for hours.
I am lucky enough to have a decent size room in my basement but chose the layout to be mainly a switching layout, although I can run trains continuously with the aid of hidden staging tracks.
Best of all, I can see and work on it.