Thanks for the positive feedback Perineum. I'll refrain from posting any jokes about your mom.
So, I found the Serious Sam HD: Gold Edition on special for $10 on Steam today. It includes SS:1 HD and SS:2 HD, and the original versions as well.
Save 75% on Serious Sam HD: Gold Edition on Steam
Direct2Drive's daily specials are the X-Com Complete bundle for $5.95 and Section 8 for $14.95.
Summer Ends Event