My universal player is dying. Upgrade suggestions?

I have a Denon 2910 universal player. I would like to get something to replace it that would significantly improve SACD & DVD audio playback, without spending too much $$$. I am willing to spend up to $800 on a player. Used would be fine...
I just bought a used 3910 for $250. used 5910ci's would be under $800.
When you say "dying" what do you mean? won't play some discs, skips? The special Blue Smoke has escaped? (that is usally what happens to tube equipment!)
Nope, no blue smoke... all my tubes are fine, it's always the solid state stuff that starts failing. The player refuses to send anything other than stereo signals, the front screen stays black while playing, the player refuses to acknowledge any remotes... crabby fellow, won't cooperate.
The universal player just doesn't ad up at all when it comes to reliability. They all seem to fail one way or another in there ability to read shortly after purchase.
Which is better, the Denon 5910 or the NAD M-55?
Oppo BDP-83SE. Genuine bargain.
I've had a Denon 2910 for a number of years and haven't had any problems. I think you'll be hard pressed to find something significantly better for your price. The 3910 has the same video circuit and slightly better audio. The 5910 is another step up, but I don't how much. Oppo offers a great bang for the buck, but have you seen/felt its construction? It's cheap in comparison to Denon.
Yeah, my 2910 is about 4 years old. I never had an issue with it before. I figure the cost of repair warrants an upgrade. I am curious about the Oppo. It gets good reviews and uses Sabre DAC chips. I have an iDecco which uses a Sabre chip & it blows my 2910 away with redbook playback, so I am tempted to replace the Denon with an Oppo at this time... I would like my surround sound to be as smooth and detailed as my two channel playback. I just don't know how to go about it.