You could try Defragging your games:
Right Click on anygame you want to defrag, click Properties, the goto the Local files tab and hit Fragment Cache Files. For GE:S, might have to defrag Source SDK Base - OrangeBox, I believe.
And as I type this there are about 6 people playing GE:S. Check how many servers you see, should be around 30 servers. Sometimes there are dead times, but its the afternoon so should be atleast 6 people on rite now.