I like uphill or flat finishes. I hate finishes where the preceding straight is a hill (i.e. up hill, turn, 300 meters to line).
I like 90 deg turns. Nothing like diving into a turn.
New London's crit had a 90 left, 90 right, 90 left, 180 left, 90 right, 45 left, downhill, 90 left, uphill to finish. All roads relatively narrow. Loved it. I think the loop was under a mile long.
I also like Bethel (0.8 mile, no real turns, uphill finish) simply because I seem to have the hang of that place. Also I promote the race, but I like the race because I can do well there.
New Britain I like too. Slight downhill to last turn, then flat finish. I've never won a summer race there but I place there consistently.
The most challenging course ever was the final race of the Tour of Michigan. 8 x 90 deg turns, 1/2 mile course, flat, 100? riders, in the rain. Dry would have been better, but it was a crazy awesome race. I think we did 50 laps since all the races in the TdM were 25 miles for us.
cdr