With a collection this big (and trust me, it seems only to expand) it's useful to find ways to trim down the collection so that you don't seem like some crazy, obsessed, board-game hoarding nut job (cue the "I'm fine...I can quit any time!" line). If you're worried about being considered a nut job, I have a few helpful tips to assist you in trimming down your board game collection to only the absolute necessities (and maybe one or two guilty pleasures too).
1. Consider Similarities: I like deck-building games and worker-placement games the most out of any options, but I don't need toown every single one I've ever played. Take a good, hard look at your collection and spend some time considering what the games have in common, and what each one offers individually. You can have multiple deck-builders; there's theme, player count, and difficulty to factor in, amongst other things, so it makes sense to have more than one if that's a mechanic you enjoy. But, if you find that you own a fair few games like that, and some are just a little too close to call, think about getting rid of one or two so that you don't have to keep choosing between them. Just keep your favorites!
2. Think Before You Buy: This goes along with Tip #1, but also helps to encompass expansions. I love having the ability to expand on some of my favorite games, but not every game I play is in need of an expansion. Before you buy every add-on to Settlers of Catan or Smallworld, weigh how often you actually play the base game. If it comes to less than twice a month, you probably don't need more add-ons to the same game. Save the money for something more useful.
3. Consider Your Audience: By this I, of course, mean, think about who you're playing games with the most often. If you have a big family with a lot of different interests, stock up! Make sure there's always something everyone will enjoy on the shelf! But, if you currently live with just one other person and you notice that some of your games are collecting dust while others are played weekly, maybe get rid of those that don't see too much light. If the #1 person you play with isn't interested, then there's really no point in keeping it around... Why not donate it so someone else can enjoy? :)
4. Donate, Consign, Sell: Once again sliding gracefully into transitions (Gosh, I'm good at this), if you've found a handful or more of games you don't want anymore, don't just throw them out! You can donate them to a locate thrift shop or other organization so that others can enjoy it. You can also consign at a local board game shop so other hoarders...er, fans...can pick them up and you get some cash without any hassle! Or, you can sell gently used games through eBay, Craigslist, et cetera. All wonderful alternatives to just tossing games out, and awesome things to keep in mind when looking to trim down, so you don't feel like they're going to waste.
5. Play Through Them ALL: This isn't a joke. If you have a hefty collection, it might be time to play through all of what you own again instead of just playing your go-to games. Sure, maybe you loved Ticket To Ride 3 years ago, but you haven't played in a while, do you still like it? Once you've given everything a fresh run-through, you'll be able to more easily determine what's worth saving and what can become someone else's obsession.
Overall, it's fine to have a great big supply of games, but don't keep things on the shelf "just because." Keep your faves, keep a few party games and classics (like Monopoly and Codenames), but don't hang on to every version of Clue you've ever seen, they're not all that different. Keeping a slightly smaller collection will ensure you're always playing something you love and not just playing something because it's there.
Happy gaming folks!