Games...

Games!

Games. What makes 'em good?

Number one: Do NOT try to imitate real life! People don't play games to relive elements of the boring lives they lead, they play games to have some fun!
The right way: Saints Row 2. The game is absolutely whacky, and you can just feel the potential for madness flowing over you, but it's fucking hilarious!
The wrong way: GTA IV. If you want to know what's wrong with it, just watch the Zero Punctuation review of Saints Row 2, you'll see! In short; games should not be as dull as normal life!

Number two: Give the main character some...well...fucking character! The GTA III-series went through this like a textbook. It started out with Claude, a useless, mute, doormat with all the personality of a jar of peas. Then it went on to a serious badass, AKA Tommy Vercetti, who knew he wanted to rule the city and he was damn well going to do just that. It all ended with the brilliant social satire of the stereotypical jerks of San Andreas.
Maybe it's just me, but I simply could never really connect with Gordon Freeman because he never said a damn word and just followed people's orders all the time. It gets rather pathetic in the second game, when he comes back as the great saviour of mankind and everyone thinks he's the best thing in the world, yet all he does is follow others, he never ever takes any initiative.

Number three: Well...who gives a damn about number three, if you were a game developer who actually used his brain rather than his scrotum for thought processes and thus could fathom the first two points, THEN we could talk about number three.