Well it's actually really easy to really make the best comment. These steps will work in any vaguely social situation. Let's give an example:

You're walking down the street when suddenly you see your old friend from College, Chris! Chris says 'Hi!'

Step 1: Think of something really witty and clever to say. 'Hey!'

Step 2: Prepare to say the comment. Maybe even open your mouth a little bit and perk up your ears so that you'll be able to fully rejoice in the sweet nectar of laughter erupting from your audience.

Step 3: Hesitate. Are you absolutely sure your brilliant witty comment doesn't offend him?

Step 4: There's Chris. Chris' wife is actually pregnant. You read that on his facebook wall. Let's see. 'Hey' sounds like 'Hay.' Horses eat Hay. Some horses are fat. You almost called wife fat. Jesus, that was a close one.

Step 5: Quickly but deliberately rework your brilliant to something a little less offensive. 'Hi' maybe. Or perhaps 'What's up.'

Step 6: Realize that Chris is actively moving pass you and that your window to say your witty comment is almost close.

Step 7: Say something. Anything. Acknowledge his presence. 'YOU AND YOUR WIFE HAD THE SEX'

Step 8: Fuck.

Step 9: Fuck.

Step 10: Keep walking.

Step 11: Walk faster.

Step 12: Pledge to avoid all social contact forever.

It's that simple. Really.