For the fun of it, I checked the builds that I covered in 2010. There were 46 of them (I started in November of 2010). Of those 46, only 8 are still around. There are more builds that have survived since then, I am just doing a review of those I had the chance to blog during 2010, and I know most of the builds mentioned below had already been in existence a while.
Pride Isle, the 2Xtreme store, is still around, with the space station and the asteriods that reminded so much of 'The Little Prince'.
Opera Joven has changed a bit. I liked the depiction of the desert it had way back then, but it is still basically an introduction to Mexico, with the Cathedral of Guadaljara still prominent.
Catalunya Virtual has also changed, more so than Opera Joven, but the labyrinth is still present.
Glanduin was closed when I tried to reach it yesterday, I hope this is just temporary, but I went there late in 2015, and it was as lovely as ever.
Junkyard Blues's club is still popular, the rest of the sim has changed a bit but maintains its atmosphere.
Passionflower Island hasn't changed one bit.
The skybox of China has remained stable
Shinda has changed a bit. This sim, as well as Glanduin and Junkyard Blues, were the best kept up to date with advances in mesh and objects (Glanduin receives particularly good marks for this).
In general I would say that sims that have not changed much or at all show their age, but the fact that some survived over 5 years is a great news story.