I'm a "Why didn't you warn me?!" kind of guy! I just love being in the middle of something and suddenly I hear... "plim!" Trophy found! Yeeeeeeeee!

Unfortunately, I misclicked and voted for "Right on schedule". Count one vote less for it.

While it's debateable which kind of reward is best, I'll tell you which one is the worst: In Magna Carta 2 on the 360, there are about 5 Achievements that can ONLY be earned by buying DLC. "What's wrong with that?", you ask? Well, the DLC is three horrible cutscenes and some weapons.

You get achievements for watching the horrible "cutscenes" that you have to pay for. I downloaded them a week ago and I STILL can't make it through one of 'em! They aren't even really cutscenes. It's just two characters acting out a scene while you use your imagination (wtf is that?) to tell what's going on. It's a friggin' radio show!!

Also, I love Magna Carta 2. It's fun.

Right on schedule.

If I need a strategy guide to achieve something in the game then the developers screwed up.

I like the "Why didn't you warn me" one's best...surprise achievements FTW!

I agree with Nordlead though, I also really like the ones that challenge you to do something reasonably achievable to earn them.

'why didn't you warn me'. I do rather like knowing there's probably a Trophy for taking the time to pet every Yak in the village and them finding out there really is.

'right on schedule' are kind of boring and I don't tend to notice them. If anything I dislike them as they tend to give away how far you are through, etc.

'I need a guide' I could do without. I really can't be bothered with the whole 'hang there for 2 minutes, walk over to there, knock over a passing granny then hop three times in place' totally random Trophy you'd never, ever get without actually looking it up or knowing the developers.

In general, the best Trophies/Achievements, as TRio_Zen (and I guess Nordlead reading his post) point out are those that challenge you fairly but are reasonable in context for the game.

"Why didn't you warn me!?" I love those, they make me want to play longer for some reason.

Trophies for things you HAVE to do to complete the game seem a bit lame to me. It's like giving someone a reward for getting up in the morning. Trophies for things you have to make particular effor to complete, and which provide you with some challenge as a gamer, but don't take you too far off the path of the game are fun and satisfying.

Mystery trophies, unless they are really easy to get or you almost stumble over them, seem a bit of a waste. It's only the platinum hounds who will really seek out those ones.

So, IMO, trophies that are known optional challenges and add to the gaming experience are the best.

That's pretty much how I see it.  The former are too uninteresting and the mystery too annoying to seek out, but the good ones that take a little effort outside the normal game are pretty good.