Megadeth is really a hit & miss band for me. I classify their albums this way.
REALLY like and would consider about as good as ANYTHING by just about ANY band in my collection:
-RIP
-Countdown
-Youthanasia
-Hidden Treasures
-Risk
Enjoy some songs every now and then:
-Cryptic Writings
-The World Needs a Hero
As far as the rest, the newer albums are okay, but never really grabbed me as a whole. I still listen every now and then, but for some reason, these never really clicked with me. The older albums pre-RIP never clicked either, but I prefer the new stuff to the old if I had to choose.