I just can't stand collectathons. I mean, 8 red coins in SM64 was all well and good, but 100 purple coins? And they're hidden all over, so that if you miss one in a hard-to-find spot and die, then you have to start all over from 0? No, thanks. :)

An example of a game that is easy to complete 100 %: MK64, no staff ghost data, really only about winning every tournament.

It depends on a lot of factors for me whether or not I beat a game 100%.

I just picked up a PS2 and have been playing God of War, I'm on the final boss battle for God Mode. Definitely a great game, but God Mode in the game feels cheesy: the enemies didn't become more complex, just a lot longer to take down and they do more damage. Sometime around the 15th time you bounce the same minotaur it becomes boring and tiresome.

I may not beat Ares this time around, but I already have on easy, normal, and hard. God Mode was disappointing.

If you haven't played it, don't let my assessment of God Mode discourage you. That game alone was worth the price of the PS2. I swear GoW could almost turn me into a Sony fanboy :O

By contrast, Super Swing Golf was definitely worth getting 100% done as you have all the characters and items and a ton of cash to gear them up. It's great for playing with friends when you have like 8 characters and 12 courses (I think, I'd have to check again).

It really depends, but my main focus is local multiplayer. GoW was something of an odd duck since my wife really loved sitting down and watching just for the story.

People who strive for 100% completion for its own sake are losers.

The point of playing a game is to have fun.  If you get 100% along the way, that's awesome.  However, if getting 100% requiring going out of your way, grinding for hours, doing other boring/repetitive tasks, and just not having fun then getting 100% is worthless.  It doesn't show that you are a good or skilled gamer, it shows just how worthless your time is.

 I definitely wasn't hardcore enough - finding all the stupid blue coins, seemed like such a waste of time.

I like to finish games 100% but there's also the question "will I be able to". Perhaps too difficult or impossible, like I missed a dungeon in DQVIII which made me then impossible to finish it entirely. Most RPG's you're not even sure if you have finished it for the 100%.

@Choir... eh.. you mean red coins, right?

 You are too casual. J/K. Getting 120 sprites was more annoying than challenging.

On topic: I only go for 100% if there is some kind of reward or the game is really good. I could beat 3 crappy games in the time it would take to reach 100% in other games. I hate stupid 100% requirements like Blast Corps platinum medals. It would take the entire N64 era to achieve all platinum medals.

 No, I mean blue coins...  You know the ones that you get a Shine for every 10 you find anywhere in any level?  So annoying.

I just play my games til they stop being fun. That's what games are meant to be about right? Why would anyone want to turn them into a boring chore? If you find completing a game 100% boring then go complete your boring homework 100% instead!

I don't normally get 100%, but I typically come close, but I also don't use guides or Rolstoppables to find hidden things.

For example:
99% on Metroid Prime 3
99% on Burnout 3 (or whatever percent, beat all but 1 race, and had everything else)

However, I do have 100% on all Mario games, and other good games where it doesn't take a guide to figure out what I even need to do.