One of my favourite sights in rugby is a flowing attack, where the ball is passed through several attackers running at full pace. Not handovers, but fullblooded passes across 10 yards or more. Extra marks for an unexpected change of direction.
Definitely one of the most thrilling sights is when that happens, it's an onrushing wave of attacking players that can't help but sweep to a try. Unless you're the Chiefs playing the Sharks and have 3 potential tries swiped away because of small errors.

I'm currently working through a whole season of missed Super 14, especially those which were close (see above Chiefs v. Sharks comment).