How many plays can you get out of a good record?

I have LP's I have played since the 1960's. I also have LP's I bought that were produced in the 50's/60's.  Some sound fantastic still. Other's were probably played with inferior cartridges, tables, arms, poor set-ups, and mishandled, including my own (not unusual for the time really....it's 'all we had', and did not angst over record care as we do today). Those may not sound as good, obviously, but still very playable, and some that were taken care of, close to or as good as my newest vinyl today. 

Keep you table/cart properly set-up and renewed when necessary, and your LP's clean and properly cared for, and obviously they will last for decades, easily.

Been playing Muddy Waters on Chess live at Mr Kellys for over 40 years still sounds great.I always use a supper high quality Moving Coil and tonearm.

Under the best of circumstances, quite a few. The best of circumstances are not common. The best of circumstances is a clean dust free record played with a perfectly oriented modern line contact stylus that has been polished to the highest standards.

Assuming you use both sides, a little shorter than McBeth.

@erik_squires 

Aye, now I understand:  Macbeth must've ruined his LP's using an old stylus, prompting this soliloquy!

"Tomorrow, and tomorrow, and tomorrow,
Creeps in this petty pace from day to day
To the last syllable of recorded time,
And all our yesterdays have lighted fools
The way to dusty death. Out, out, brief candle!
Life’s but a walking shadow, a poor player
That struts and frets his hour upon the stage
And then is heard no more: it is a tale
Told by an idiot, full of sound and fury,
Signifying nothing."