1 Construction jobs
2 Economic diversification (OKC is too reliant on oil and govt)
3 Embarrass the Stimulus
4 The pride we take in MAPS projects
5 A boost in downtown investment
6 More constant events downtown
7 Healthier community
8 Urban 'renaissance'
9 A foundation laid for the future
10 Raise OKC's profile

More detail and explanation, pictures, etc on all of these..
A Downtown ontheRange: Top Ten Reasons to Vote YES on Dec. 8th

I just think that these would be the most convincing points for someone who is on the fence regarding how they'll vote on MAPS 3.