Keep in mind that even the best, most expensive hotels in the world can get bedbugs, through no fault of their own. They are usually brought in by guests in luggage after they've been somewhere with an infestation. No one, include a housekeeper, will even know they're there until they start biting and making themselves known.
The best defense is vigilance. Before bringing your luggage into the room, check the beds. The bugs like to hang out in the mattress seams until food comes (that would be us!). Pull up all coverings at the foot of the beds until you can directly see the mattress. Look around the seams for black or red dots. If you don't find any, spot check other areas of the beds as well. I've also heard about them being in drawers where someone might have stored infested clothing. It is recommended that you not use hotel room drawers for your clothes. If you absolutely have to, check them carefully for bugs and cleanliness before storing your clothes. I prefer to live out of my suitcase, and hang up anything that wrinkles easily. You can also spot-check the edges of the carpet, especially in the dark closet areas for bugs. Don't bring your luggage in until you've looked around. If you notice anything suspicious, notify the manager right away. It's best to ask someone to come to the room so you can show them what you've found. Ask for another room away from that one.
I wouldn't necessarily fault or avoid any hotel that's had bedbug reports. I would, however, avoid a hotel where management does not respond appropriately. I've seen reviews where a guest reported bedbugs and the management either denied the problem or was indifferent. On the other hand, I've seen reports where management took it very seriously, assigned the guest another room, and stopped renting the infested room until pest control was called and it had been cleared. That's the kind of response that would make me consider staying at the hotel again (all other things being satisfactory).