Of course, if price is no object and you're willing to spend anything to get the very best home entertainment system, then there is a lot of expensive specialist equipment out there for you.
The first thing you will probably want to spend money on is a better sound system – audiophiles are ever coming up with new ways to fill rooms with speakers, and get a better sound experience. If all the wires running across your floor would upset you, then do not worry, as you can get wireless surround sound speakers for not too much more than normal ones.
If your sound system is good enough, you might even want to have sound insulation put into whatever room the home entertainment system is in, to keep the sound from escaping and disturbing others. This means that you can have the sound up very loud without having to worry about what anyone thinks of you.
When you get to the point of buying a separate TV from your normal TV just to play films on, you might think about buying a projector instead. The main problem with projectors is that they're not much good for normal TV viewing, but if you're planning to keep one away and use it just for films, then it can be much better quality, as long as you have a clear wall to point it at.
To take it to the next level, you may consider putting your home cinema in its own 'cinema room' (sometimes called a 'screening room'), complete with sound insulation, a screen for a projector and extra-comfortable cinema-style seating . Some enthusiasts go as far as to decorate this room to look like a cinema, with red curtains, movie posters, and a popcorn machine. If you do go this far, then you do not have to keep the cinema cinema just for yourself – you can invite friends over to enjoy it too, and even hold screenings of particularly rare and good films.