Here is Han shooting Greedo without the "Yes, I bet you have" line.

I think the scene would play better without that line. You only hear one shot, and for a moment it looks like it's Greedo who shot, but when the smoke clears you see that it's Han who shot.

I don't think Han would waste time on the one-liner and give Greedo more opportunity to shoot him.

I also think it's funnier without the one-liner. "I've been looking forward to this for a long time." BAM. He's dead. The irony is obvious and we don't need Han to point it out.

Another virtue of cutting the line is that it improves continuity of Han's position. In the original, Han is leaning back before the one liner, then he leans forward a little when he says "I bet you have," then he shoots, then he's leaning back again before getting up. In this version, Han never leans forward, so it makes sense that he is still leaning back when the smoke clears. (As presented here, it introduces a worse problem, which is the jump cut at the moment of the blast, but that could be corrected by a skilled editor.)

This video is edited from the "STAR WARS: EP IV 2004 Special Edition REVISITED" fanedit by Adywan. Adywan is responsible for the more realistic and expressive Greedo. I'm responsible for cutting out "Yes, I bet you have" and for the blast being way too far to the right.

For more information on Adywan's absolutely AMAZING fan edit, go to originaltrilogy.com or fanedit.org.