The capacitors could be reused - generally they're 1500, 2200 or 3300uF 6.3v/10v/16v (some for 3.3v rail and 5v rail , some for 12v rail).
There's one or more optocouplers that you could reuse, they're pretty generic.
You can also re-use some of the inductors, for example if you want to play with some switching regulators like mc34063...
Other than that... lots of passives like resistors, some diodes, but usually they're either surface mounted or the leads are too short to be of any use.
Some have some a 7912 and maybe even a 7905, to produce -12v and -5v, these are jellybean linear regulators..
The transformers are probably the least useful for hobby stuff.
I don't advise taking it apart, it could be useful in the future for some projects ...