Here are my rankings for autonomous based purely on spectator value:
1. 2006
2. 2003
3. 2005
4. 2004
5. 2007
2006 was the pinnacle of autonomous. It had the right mix of excitement, scoring and difficulty. It was a full contact chess match. All the bots started in the center of the field so if you could score in auto you could aways try to hit a scorer. It was so dynamic (not just the same old routine) that it was memorable. My favorite memories were:
NJ - After being stopped in the previous Finals match, team 25 used a different auto routine (they had always used the same one) to avoid the defense and score. The whole crowd audibly noticed the new routine
. How many other games did the crowd (not scouts) notice or care about changes in an auto routines?
PIT - After we (365) took the camera off for weight we played mostly auto D. we played against this one bot (which shot blindly), several times and we always sent it firing into the crowd. The next time they were on the other side of the field so I walked over to where the field reseters were sitting and said "Heads up! As soon the match starts there will be 10 balls coming right for you." My prediction was right on and they caught the balls with the laundry cart.
CMP - We got our camera back and working. In one match 462 fit us before we could get set in our shooting spot and nearly
flipped us 
. Then our 1 or 2 wheels on the floor manged to turn us back on target. We started shooting and hit 5 for 5
2003: Who didn't love watching bots race to the middle and destroy that box wall?
2005: Introduced starting game pieces so there was scoring at least of the hanging tetra type almost every match.
2004: If you could/wanted to, knocking the bonus ball off triggered the ball dump which was pretty cool, especially if your partner caught all of them
2007: It would be kinda neat if 90% of the robot actually did anything. Most of the time everyone is just staring at blink orange light on 6 stationary robots. It is so boring it is comical. It makes the start of the match anticlimactic. And in those rare matches where a robot actually moves and manages to place a keeper, everyone is exited till they look at the scoreboard see 2-0, worthless.
I don't mind a challenge but this game took so many measures to make it random and difficult, it caused teams to not try, which is not inspiring at all. To those that tried very hard and succeeded, the points are exactly a BIG reward. It is almost like they knew that most teams wouldn't be up to the challenge so they didn't give out an auto bonus to make the game more "fair" for the autoless teams.