My Japanese Black Join Avenue is currently Rank 29 and I'm just trying to max out the discounts and the final shop on the street, which is a Raffle Shop. Got one of every shop, apart from no Nursery which is replaced with an additional cafe.
My English White Avenue is currently at Rank 12 thanks to the Magnemite Coil. I've got 1 Florist, 1 Cafe, 1 Fitness, 1 Raffle, 2 Markets and 2 Antique Shops, but they're around the rank 5 status for each of them. I actually prefer this current setup against my Japanese Black setup mostly because I'm using more of the shops on a daily basis, the Markets and Antique Shops inparticular because they offer very appealing bargains and you can farm some good stuff from the antique sellers which make them worthwhile in the long run (6 Big Nuggets on the Japanese cart = stinking rich)
In terms of competitive shops, this really depends on what you want out of it to help from a competitive sense. Heavy breeders will almost certainly want to invest in a Nursery, although you can argue that with the breeding getting messed up in this version it isn't as useful unless you trade eggs over from the preceding games. If your doing EV training I strongly recommend investing in Markets, Fitness and Bistros. Markets are useful as you get mega discounts on the vitamins that each of them sells and if you can get two Markets selling the whole range you are set from that perspective.
The Fitness and Bistro also provide EV Training options, but these are only really value for money once to maximise the entire avenue's discount on all goods (maxes out at 40%), which make them better value for money than vitamins bought from a regular store. You also get items that raise pokemon levels at these two, including one at the Bistros once you reach rank 10 on the shop that raises level by 8. Using the levelling options does mean you miss any level-up moves at the levels you jump though, but at the higher end of the scale, they make excellent items to boost you to the level 100s.
If you also require EV-reduction services, I'd recommend getting a Salon, and possibly a Florist as they provide the relevant services. I recommend a Florist anyways, as you can buy the mulch he sells there and make an arbitrage profit using the Breeder in Mistralton City on every item. The Markets are also good for abusing arbitrage opportunities once they start selling you RageCandyBars, Old Gateaus and Lava Cookies with that Maid on Route 5. They've been especially useful in funding my uses of the level training services on the avenues every so often.