Where to avoid in Oahu?
In thirty years of dining on O`ahu (as a tourist, as I have never lived there), I have had meals, that I would not wish to repeat. In very general terms, there is not much "bad" food on O`ahu. However, there are less inspiring restaurants, and also restaurants that do have bad nights - sometimes very bad nights. I've had them. I've also experienced good to great nights at the same spots, on previous, or later trips. It does happen. The best chef cannot guarantee 100% all of the time, though some seem to come very close.
I am a fan of several Waikiki restaurants and, depending on exactly how one defines "Waikiki," even more. Still, many spots do come up short. Unfortuantely for them, we do not have the time to do 3 dinners at all, just to be sure. I could get "ca-ca," and the next CH reviewer hit 'em right. That does not make my review a bad one, or their's a good one - it was just different, when we each dined at restaurant X.
In horribly general terms, I'd avoid anything with "smorgasbord" in the name. I've also found that references to "paradise" are often not up to par. OTOH, if the names "Roy's," "Alan Wong," or "Sam Choy" appear in the name, the likelihood that the food will be good to great, is there. The night you go, might not be their 100% night, but that is life.
Though most of our dining experiences are definitely in the "high-end" spots, we've had great meals at such restaurants as the Shorebird Broiler at the Outrigger. Yeah, it's a bit touristy, and not on the list of "must-dos," but every meal there was good and worth the $, by Hawai`i standards.
Probably, the easiest way to do it would be for you to list the places, that you are thinking of, and then people can comment on those.
With the great food on O`ahu, it's hard to get bad food. It can happen, but not with regularity.
You imagine right. But there are also enough great places to eat that you can do very well for yourself at just about any price point.
If you're only on-island for a week or two, it will be far easier to find a bunch of places you want to go and not worry about trying to identify the places to avoid. A quick search on this forum will turn up lots of good recommendations.
As a general rule, though, you're going to find higher prices for lower quality anyplace that everybody on the street is a tourist. So you'll get far better QPV in Chinatown than in Waikiki.
sku is right, there is also great food just outside Waikiki, but I have to take some exception to the statement that there isn't much good food. There is some excellent food in Waikiki, but you are generally going to have to pay high prices to get it. LaMer, Roy's, Nobu, DK Steakhouse, Bali by the Sea, and a few others are frequently cited as good places to eat, all of which are in Waikiki. And all of which are expensive - even by Hawaii standards. My one place to avoid is in Waikiki, Cheeseburger-in-Paradise (but i know of people who like it there). check out some of these threads for places that you might like rather than places to avoid:
(oahu report) http://www.chowhound.com/topics/442201
(best hole in the wall) http://www.chowhound.com/topics/421684
(sunday dinner waikiki) http://www.chowhound.com/topics/444640
(cheap eats Honolulu) http://www.chowhound.com/topics/424931
(Oahu Cheap & Tasty) http://www.chowhound.com/topics/259032
(Downtown Honolulu) http://www.chowhound.com/topics/427704
(Best Fish) http://www.chowhound.com/topics/468012