My local Performance bike shop moved, so they had a grand opening at their new location. Both this weekend and last weekend, they were giving away $20 of in-store credit to the first 100 people at the store each day (Friday, Saturday, Sunday). That's $6,000 per weekend! I went last weekend with my dad and we got $40 of credit. We got a pair of sunglasses, bar tape, and some other goodies. This morning, we went and again got $40 of credit. I got a jersey that was originally $70, marked down to $50 for 50% off. With the credit, that made it only $5. Talk about a steal! But for tools, I was contemplating between a Park CN-10 (cable cutter, $37.95) or a Park FR-5G (SRAmano cassette lockring remover, $8) and a "Spin Doctor" chainwhip. I decided that I wouldn't use the cable cutter all that much (though I have been using the one at the co-op a lot because I just converted to white cables) and got the lockring tool and chainwhip. I will be using them about twice a month to clean my drivetrain. So I scored $105 worth of stuff for only $8 out of pocket (entirely legally too! )
Tl;dr: If you had to choose one tool that you use/like the most, what would it be?