What I love most is the competition, the conflict, the dispute, and not the victory itself. I have often found some of my victories boring and some of my defeats fascinating (though I must admit that the worst combination is a boring defeat). Of course victory is the objective, but it's the "getting there" that is important, not the actual arrival.
I dislike it when I play with players that willingly won't compete (who create a private objective, such as ingame revenge, letting your girlfriend win, wants to be the player with the most houses when that does not award points or is clearly not a good path for victory, etc). I would not want watch an interesting movie with someoene who wants to chat all the way through, why am I arrogant if I don't want to play with someone who is doing something entirely different from what should be done? Would you share a 2-seat kayak with somebody who doesn't want to go to where you're going?
Games to me are logic systems for competition. A game's worth to me is how intricate and interesting the system is, how everything is tied together. I prefer heavy games, economic games, games with direct conflict. Lack of interaction or weak interaction go straight to the "won't even give it a first play" category.
Theme and good-looking art is unimportant: nice to have, but hardly necessary. The most apt comparison is with food: theme is to a game like appearance is to a plate (as in, it's not really what it is about).
Don't get me wrong, I have nothing against people that have different objectives in this hobby (unlike they seem to have with me, always complaining I should be less competitive and more casual). I don't think "I have it right and they have it wrong". And I'm not against lightheartedness in general (I'm even willing to play a party game now and then: I love Dixit). I just find that "lightheartedness" and gaming to be separate things for me. I like my strategy unmessed by other things, and like my other things (sorry, couldn't think of a better word) unmessed by my strategy.
And since gaming is by necessity a social hobby, these different objectives (wrt gaming) tend to sometimes clash when they are put together.
Regarding having a "I like a small collection" microbadge while owning 80+ games, it's just to reflect that my collection is fine-tuned to my taste in games. I will likely not keep a game that's "okay" or merely "good". For me to keep a game that's just good, it has to be pretty unique. It's not just a financial matter (getting some money back when I sell it), I actually like looking at my gaming shelf and see that I would play any of my games pretty much anytime. Example: I like agricola, I'm happy to play it now and then, if someone were to give me a copy, I would gladly sell it. If someone gave me a copy and forbid me to sell it, I would give it to a friend. If I were prohibited to sell it and give it away, I would think about refusing it. I take enjoyment out of having a fine-tuned collection.
Top 10: The 10 best games I've played.
Hot 10: Used to be the games that I would like the most to try out, but now it's just a top 10 of my favorite 18xx games.
Preordered: Use it for games that haven't arrived yet and AoS expansions, since it annoys me that BGG's system adds expansions in the "number of games owned" list.
My avatar is a cut version (oh, what heresy) of a Magritte painting called "Le Seducteur". It's a very literal sea-ship, and I really like it