Most of my games never get proper names; usually they're just called "Project <InsertCodeNameHere>", then I start making something else when I get a new idea. Since I love astrophysics and cosmology, I usually name my games after celestial objects, depending on the planned scope of the project. Small games get named after moons and dwarf planets, medium ones get named after planets, big games get named after stars, and super-mega-gigantic-AAA-sized games get named after galaxies.
Some examples: Project Eris, Project Deneb, Project Mercury. All frozen in mid-development for a few years, sadly.
As for the final names, I always look for something that fits the theme or purpose of the game. I use a thesaurus, brainstorm all kinds of words and phrases, and sort them based on how much I like them.
My only playable game is (currently) called Forsaken Airspace, chosen from over 20 names. It's a flight combat game full of things that want to kill you, with a bit of a grim backstory. And most importantly, no other games used it.
Edit: I've yet to find a game title that I hate, so I guess I don't care what it's called as long as it works. I don't like when it has a super generic name that's impossible to search, though.