Whats your price range? Your requirements are minimal so there are alot of possible fits.
If money isn't a issue, I strongly recommend the Asus RT-N66U. I can't promise it will fix your problem, since I don't know what your problem IS, but I can say I personally own one and think its the best consumer Wifi N router on the market right now. I wouldn't say its the easiest or most simple device, but the UI is good and you can even upgrade to dd-WRT if you prefer something else. As you can see, its sold out on Newegg since its now a popular device.