I can only think of a few that really "closed" and in all cases they ran into serious financial difficulties whether due to poor planning or fraud or...

Mostly I think we see programs that constantly reinvent themselves, rebuild, redesign, revamp... not always for the better.

As for good affiliate programs? Wow, loaded question!
There are probably a bunch i could call out, but I think that the simplest ones usually work the best. Pride Studios has always maintained a strong following and webmasters seem to be very loyal to them.
Buddy Profits is another one that has always been strong and only seems to be going up.
I know many webmasters who are doing great with Bait Bus and Evan Rivers from Bang Bros. which is a predominantly straight company that has invested in and really promoted their two gay offerings. It's a good program.

Then... what do you mean by "good"? Highly converting or a great affiliate site to model oneself upon?