Holy shit, just had an epic 1v1. I started off getting an easy 3-0 lead in about 20 seconds (actually expected him to rage-quit at that point, but was happily surprised that he didn't), but then I got sloppy, and a while later it was 4-4. Then he got another one in, and it was 4-5. I thought to myself "I cannot lose this, not with the start I had!", and with 30 seconds to go I got the equalizer in. "Sigh, good, I'll make it to overtime at least!" But then I put the winning 6-5 in, and it was a done deal. Just felt so good.
In some ways I actually like 1v1 the best. It's just a pure test of strength and skill between two players on equal footing, with no random teammates to shift the balance in or against your favor.