We are leaving for Berlin, Germany on MONDAY to visit my son studying abroad.
Where can we stay?
Moderately priced - SAFE, CLEAN.
We would like to be near him - Gneisenau Strasse Berlin, Berlin
My son says to stay WEST Berlin because it's nicer.
Please Help
Thanks so much!

Send your son on a scouting mission - I bet you trust his advice more than folks here whose tastes and budgets may not agree with yours, no matter how helpful they may be.

You could at least find out which U-Bahn station is nearest to him and stay somewhere along that line, if possible. That would at least make for easier travel. Someone here might have better information for you if you could give a more specific location.

I find in general that hotels in Berlin are more reasonably priced than other large cities.

The street you mention is in the east part of Berlin
( which is more interesting and where most museums are).
The west is nice but a very long way from your son's address.

You might look for accommodation near Check Point Charlie
...it is a touristy area not very far (by public transit ) from where your son is staying.

@danon my son just told us that we should look in neighborhoods called Matte and Charlottenburg. Any suggestions?

Maybe he means "Mitte"? That's the central so called "touristy" part on the east side, and a good location.

Charlottenburg area is in the west.