I have never played in a tournament, and I would be bringing other clubs if I was just playing for fun, but given that score matters, I would take these:

Driving Iron: Reliable, good roll
5-wood: Same carry as DI, but sticks, and is easier to use from the fairway
6 iron: My favorite
Pitching wedge: My favorite short club
Putter: Since we are allowed the luxury of 5 clubs, I might as well bring it....