On the Xbox 360, obviously. Achievements have since their arrival been heralded as the greatest thing to hit console gaming since the notion of saving your game between levels appeared. (Believe me that took a very long time to arrive.) The concept is behind them is utterly simple, yet the implementation was pulled off very effectively, surprisingly so. It is as follows, designers are told that their game must have achievements in it. They must add up to 1,000 points, and the designers are pretty well free to make them whatever they want. When designers make achievements something notable it can really add to your bragging rights and also serves as a visible testament that you actually accomplished the "achievement". At long last gamers can no longer proclaim their greatness without any viable way to test it. You can simply look up that person's gamertag and voila! You can find out right there if they are as good as the boast. Further boosting the lure of the achievement is the fact that an overall gamerscore is generated adding all of your achievements into a single score. Making for an overall bragging rights, although given there are no actual quality control for achievements bragging about overall score is quite pointless given that if you are willing to rent every game you'll probably outpace someone who simply plays a few select games and masters them getting all 1000/1000. Thereby negating the entire allure of having achieved something.
So overall achievements are probably a good thing for the evolution of gaming right? Well overall yes. Although recently several sights I've seen around the 'webs' seem to have me concerned with the future of achievements and games.
It centers around the notion of bragging about overall "gamerscore" which, as stated above, is pointless. The system is not controlled enough to validate bragging about having the most point when you can play only 'kiddy' games and make thousands of points in a few weeks, versus someone who goes for 1000/1000 in Mass Effect. (Something that would take roughly 150 hours of gameplay, perhaps even more.)
What really has me concerned is the consumption of games solely for the acquisition of more achievement points. In this situation we have people getting games solely for their point value and nothing else. The concern with this is that game quality becomes utterly irrelevent to those 'gamerscore whores', the mere fact that it has 1000 precious points to be juiced out is reason enough to purchase the game. Hell, I'm amazed someone hasnt approached Microsoft with plans to sell achievement points outright (I could toss a joke about Avatar, but that's been beaten to death.)
The problem that I have with this situation is that it utterly destroys the merits gaming. No longer is there any reason to play a game. You purely power through it to get achievement points and then move on. One particular occurance of this was surrounding the launch of Penny Arcade's new game. (Great game by the way, very good if you're a fan of the site) A site i frequent decided that it would have an achievement contest, whereby the first to get all achievements would get to brag about having done that. No longer is merely getting the achievements, enough of an achievement for these people, they must now create further achievements out of achievements. With that game especially, I felt that rushing through the game was a disservice to the title. There are lots of little touches in the game that if you ployed through solely to get the achievements you could very well overlook them.
Further worsening this is the fact that if consumer's dont care about the content of their games, then developers will gradually get lazier and lazier, knowing that so long as they provide the achievements, the games will practically sell themselves.
Basically achievements work when you are bragging about having achieved a specific achievement over your buddies. But the overall gamerscore needs to be shot in the back and left for the dead until it gets a revamp or a reclassification of achievement points (maybe achievements earned in any game specifically aimed at 4 to 12 year olds should have their points classified under a seperate gamerscore. While hardcore games get their own as well.
Because honestly does anyone really care that you have 50,000 achievement points. I mean bravo you have played through over 50 games of which at least 35 had to shitty games that werent even worth playing except for your little achievements.
Hopefully a revamp of achievements does occur with the next iteration of the Microsoft console, but for now the system works pretty well and is indeed fun. Unless you're achievement whore in which case i reserve a special level of hatred just for you.
But that's all i got for now.