There's multiple ways to collect and I think each has their appeal.
One way is to get a lot of games, build complete libraries, and have many games from many systems all on display. You can really build a museum, even if it means getting games you don't fancy. When I go to a retro game store, I think it's really awesome to see games from all different eras. It's like you're going back in time, but to many different times, all combined in one collection. The downside is that it's more expensive and you have to get games that you might not like or play. You may feel like it's more like a job, getting special editions, collecting games in mint condition. Now some people think this is unpractical, to build complete collections and have more games than you can play. But there is some positive in this as well. It keeps you interested in your hobby, it helps you have goals, and it's fun to build libraries. Plus you'll always have games that you end up loving, games you didn't know were gonna interest you.
The other way to collect is buy less games, but games you anxiously want to play and have. Things are more simple, you'll have what you want for the most part, and you'll have more money left over to get more of the games that are favorites of yours. You will probably have less to worry
about as well. The downside is that you may never play that random, gem that you find when you collect and hunt all games. So things become more predictable compared to going out and looking for deals. Also, your wife is less likely to steal a game to test you. : ) Although that's still possible.
For me, it's kinda complicated. I collect MOSTLY for the games I really want. But at the same time, some games have nostalgic value. Some games I never had as a kid and I chase the experience I never had, but could have had. Then I collect a small amount of games whenever I get a system, since I feel slightly obligated to have some games for each system I own. I also love collecting certain genres more than others and sometimes I'll collect games just to add to a different category I'm lacking in. But all in all, I try to collect games I like and want.
Some people do it differently. Some rent games, some buy then resell, and some will just buy on PSN if they see a deal.
What's your way?