During lunch, I checked out this regional mayo question at my local supermarket located here between the 103° and 104°W parallels.
We’ve got both Hellmann’s and Best Foods. But here’s the catch: you can only buy Hellmann’s as “regular” (high-fat) and you can only buy Best Foods as the “lite” variety. So–we’ve got 'em both, but they don’t exactly compete with each other.
(If it helps, the supermarket I checked this out at is HQ’d in Albequerque, NM.)