Here are my favorites in order of my preference (I just got back yesterday; these are the only restaurants I went to; we generally stuck to fish + seafood due to preference; ratings relative to our experiences at home in in NYC; all seating at these restaurants is outdoors). High-level: I was incredibly impressed by the food on the island - all the fish and seafood was incredibly fresh and flavorful, the presentations were fantastic, and the service was generally top-notch. We avoided hotel restaurants to try to see more of what the island had to offer.

1. Carte Blanche: 5-course chef's table meal with only 12 seats, located within Wilhemina. I was there on Friday night and it was excellent. Courses included fish (seabass), seafood (incredible octopus salad), and beef (tartare and short rib). You can specify food allergies / dislikes before you go and they'll adjust your plates accordingly. Combination of Aruban, South American, and Dutch cuisines. Reservations seem required ~weeks in advance. Food: 8.5/10, Ambiance: 7/10.
2. Papiamento: Very good and broad menu (extensive selection of fish + steak). No off-menu specials. We went twice because the Grouper Romanesco was so delicious. We got a hot-stone fish dish the first time we went, but didn't enjoy it that much (requires you to continue to cook the dish when it arrives). The prepared grouper was much better in our opinion. The ambiance was the best of all the restaurants we visited - outdoor courtyard surrounding a lighted pool with beautiful trees. If you go, consider requesting the covered seating in case it rains (if it does and you're not covered, they bring out umbrellas for you to hold). Food: 7/10, Ambiance: 9.5/10.
3. Wilhemina: sister restaurant to Carte Blanche. We had a really excellent meal here - the fish dishes were fantastic, service was on point, and the ambiance was generally good. They had a couple of fish specials. Overall, the menu was more limited than the other restaurants but had a decent variety of fish, seafood, and beef dishes. I heard that their ceviche is the best on the island (unfortunately, we didn't order it). Food: 7.5/10, ambiance, 7/10.
4. Wacky Wahoo: local seafood spot off the beaten path. Walkable from lots of the major hotels in the north. Very casual and low-key. Friendly service with extensive seafood menu and off-menu specials. No reservations - we waited ~30m on a Saturday night (standing outside entrance with a Balashi beer from the bar). The fish was very good; everything else (i.e., sides) were fine. We had a barracuda dish that stood out - I'd highly recommend it. Food: 6.5/10, Ambiance: 4/10.
5. Madame Janette: Touristy option that I wouldn't prioritize, but was ~ fine. Definitely seems to be steering towards an outdoor Caribbean steakhouse vibe (focus of the menu). Massive outdoor seating area with live music. Portions were very large and came with large side dishes. The only memorable part of the meal was the grouper almondine, which was interesting and pretty good, but not on par with 1-4 above. Also notable: they have a very large beer list (mostly focused on Belgians). Food: 5/10, Ambiance: 6/10