What do you say when people ask how good at chess you are ?

I know enough to be dangerous is a good answer...lol.

If I'm in the mood to brag, I say I must be a remarkable player, because even though I've maintained my lifelong determination never to study the game, even a little, I consistently play at a barely adequate level!

"I have achieved levels of mediocrity seldom reached by others in my field"

It sound impressive, and at the same time vague.  

GM

Terrible but once I beat a NM (not telling the not important details about timeout)

I try to give them an idea of my chess ability by comparing it to sports.  I tell them I'm like a quality starter on a small college baseball team -- maybe even all-conference.  But that I was not good enough to be drafted by any of the 30 MLB teams, so, for the love of the game,  I have been playing for the Indpendent Minor League team, the Long Island Ducks, for the past 40 years.

The problem with using percentile of rated players is that tournament players are just the tip of the iceberg.  There are about 65,000 players in the USCF MSA database, but there are millions that never play rated chess, over-the-board.  So even a player with an established rating of 1250 is one of the very best in the country.  Before internet play, I was challenged at least a dozen times by non-tournament players who assured me they were very good -- the best in their family or the best in their college.  Reluctantly, I have taken up the challenge as I beat all of them but tried to let them down easy. 

No no no, do not let them down easy! Crush them and crush their egos!

Nothing better than a nice bunny-bashing to make you feel good about yourself

     Referring to the subject of this forum, when someone asks "how good at chess are you?", I don't lie, however I am economical with the truth. 

     I say things like I can win against 90% of the opponents I encounter, since most people barely know how the pieces move and are still confused about en passant. 

To a non playing friend I say "better than you would ever be".

Good, but some times I can be a moron.

Great answer to another question:  "How high's your IQ?"  (Hope you don't mind if I use your answer... )

I like this one, too.  ;-)

Usually I'm moreon than off.