Quoted from Russell:

I have a few nice machines, and I rotate frequently. (Once every 2-3 months.). I have 7 currently, and would gladly reduce that a bit.
I don't really enjoy having a "collection." For me, it starts to feel obsessive and mildly embarrassing.

Quoted from Russell:

This may be a little overly philosophical for Pinside, but here goes...
It is impossible to own every game. (though the guy in Banning, CA may make a run.) Given this fact, I like to think that I own a small sliver of the huge list of games at any one time. I will keep rotating, and will gradually experience more and more of what our hobby has to offer. It's just a mental trick, but it works for me. I just try to keep enough around for me and my family/friends to enjoy.
I make NO judgement about those who choose to do otherwise.
Personally, I enjoy simplicity. That includes minimizing material things. It avoids lots of issues that pinheads struggle with: maintenance, $$, space, spouse fretting. It also avoids the potential for obsession, which can be unhealthy.
Take it or leave it, but this is my argument for a small, frequently rotating list of games.