Every year Cushman & Wakefield puts out this report looking at retail markets across the globe. Interesting read that looks at trends, emerging markets, fundamentals, etc.
Of course it's always interesting to look at rents across NA. Jax isn't listed as there isn't really a retail district there, but it's still interesting (and Miami has the retail area of Miami Beach excluding Bal Harbor listed).
North American Rank / City / Retail Submarket/Street / Sep 2014 Rent in USD/sf/yr / Ann. Rental Growth
1. New York / Upper 5th Ave / $3,500 / 13.3% (most expensive in world)
2. New York / Times Square / $2,300 / 9.5%
3. New York / Madison Ave / $1,400 / 15.7%
4. New York / Lower 5th Ave / $1,000 / 1.5%
5. Los Angeles / Beverly Hills / $675 / 13.4%
6. San Francisco / Union Square / $650 / 30.0% (highest rent growth in world)
7. San Francisco / Post Street / $495 / 16.5%
8. Chicago / North Michigan Ave / $485 / N/A
9. Miami Beach / Lincoln Road / $325 / N/A
10. Toronto / Bloor Street / $325 / 1.6%
11. Chicago / East Oak St / $315 / N/A
12. Washington DC / Penn Quarter / $220 / N/A
13. Vancouver / Robson Street / $210 / -2.3%
14. Montreal / Rue Saint Catherine / $180 / -5.3%
15. Toronto / Downtown / $175 / 0.0%
16. Chicago / State Street / $150 / N/A
17. Washington DC / Georgetown / $150 / 7.1%
18. Boston / Newbury Street / $147 / 7.3%
19. Philadelphia / Walnut Street / $135 / 8.0%
20. Palm Beach / Worth Avenue / $125 / 6.8%
http://www.cushmanwakefield.com/~/media/global-reports/Main%20Streets%20Across%20the%20World%202014.pdf
NA markets to watch include Seattle (surprised it wasn't anywhere on the list - it would likely have higher rent than Philly/Palm Beach), Denver, Portland, San Diego, and Calgary.