It means a lot of people appreciating the said work ... 

The extremely successful games are the amazing games ... 

Not every game that we encounter should be qualified as great ...

A lot of people do appreciate the said work so again you're not making much sense here at all, amazing is not defined by extreme success either it's defined by quality. Shadow of the Colossus is an amazing game but doesn't have exetreme success.

By "appreciate" I mean that people value or treasure ... 

I would say that quality is defined by extreme success ... 

Again not every game that we love should be labelled as great ...

http://www.vgchartz.com/game/81797/call-of-duty-advanced-warfare/ 

Successful? Yes. Amazing... no. Some of the least successful games are some of the greats. Just saying.

I don't know about you but shouldn't a game that's valued by more people be the better game ? 

Which many people do, hell Fire Emblem games go on to be some of the most sort after games long after their release with people willing to pay over the odds for them so you're still not making sense at all especially with the second part. Under the logic you're employing Wii Sports is the game with the most quality in history beating out every game under the Sun, quality has never been defined by success sorry but that logic is so flawed we'll pretend it was never posted.

Not every game we like is great but so far everything you've posted has contradicted your stance on many levels, a great game is simply a high quality game for reference and quality is defined by how well put together the overall product is, sales are only in regards to how mainstream a product is.

Thats a really subjective and general way of speaking. My above example of COD is has so many counter points. Lets take Earthbound for example. People lately have been hating on COD, but it sold more than EB ever did. Does that make COD:AW better than EB? Thats a matter of opinion.

I personally hate Halo. I think its a god aweful game franchise that never once had an original idea. The story is Stargate and the gameplay is Unreal Tournament. Does that make it a bad game? Does it make it better than another game? Thats up to you.

Are you defining value by what it means to a corporation or what it means to the individual or the consumer base as a whole? Overarching and sweeping generalizations are pretty silly imo.

*edit: I've been reading a few threads on VGChartz today, seems like a lot of people are getting salty over next to nothing. Weird.

Collector's value isn't exactly what I'd call a good proposition to determine what most people value ...

Wii sports made tons of people plop down $250 so it's definitely a contender ...

Where exactly am I contradicting ? Don't just simply smear other peoples arguments without pointing the flaw ... 

How do we determine how well put together the product is ? 

What's most valuable is what the consumer base thinks ... 

Individuals alone cannot come to a consensus and a corporation cannot be the ones to define what's valuable ...

More Action RPGs are always a good idea.