I'm sure folks can tell you what players they have had positive experiences with after two years of ownership but I would think many of those models would be discontinued by now. It's probably not easy to get reliable data on this by model number and I'm sure brands have some very reliable models as well as crap models.
For what it's worth, I have owned 3 Sansa's. 280R - lasted 11 months. They replaced it with another and it lasted about a year. I had a 260R and it lasted almost 2 years. I wouldn't recommend those models from a quality standpoint.
I have a Samsung P3 which is new. Huge improvement over the Sansa's and I love many of it's features and quality of sound but who knows what I'll be saying in 2 years and it will probably be discontinued by then.
You can search on most reliable brands. A quick search got this to start with. I'm sure you will get plenty of folks to disagree.
WHAT IS THE MOST RELIABLE MP3 PLAYER? BY RELIABLE, I MEAN WILL STILL WORK AFTER SAY, 2 YEARS.