Megadeth was once one of my favorite bands. I still like them, but their not amongst my favorite bands anymore, as my taste in music has changed a lot! Slayer used to be my favorite band once, now I don't even have one cd or LP by Slayer anymore. I still enjoy Megadeth's "Rust in peace" though, as I think it might be the best thrash record ever. "Countdown.." is their second best in my opinion. I sold "Youthanasia" so it's hard to remember, but as far as I recall it was good, but not as good as it's two predecessors. "So far..." is half and half in my opinion. It has some good songs like "Into the lungs of hell", "Mary Jane" (which is also the title of a Rick James song from '78, his is about weed!). The rest of the record is pretty much stuff you just skip.
I heard "Peace sells.." a lot when I was younger, but I never really liked that record. I know a lot of people was like "Man, this sucks" in the beginning, but then came to love the record, but I don't think I'll ever come to like that record, no matter how many times I hear it.
I haven't heard "Killing is...". I borrowed "Cryptic Writings" recently and only heard it once, but I thought it was okay. Some of the stuff you skip, but I think there was some decent stuff on it. I could have done without the last song which is a complete rip-off of Metallica's "Motorbreath"!
I haven't heard "Risk" and "The world needs a hero", so I can't comment on them.
Even though thrash is pretty much gone from my musical taste, I still enjoy "Rust.." and "Countdown..." as I think there still classic records! The rest I can pretty much live without, but might be willing to buy if I find it cheap in a second hand shop.
I never got to see them live, which I think I would have enjoyed, but if they were coming to Denmark now, I don't know if I'd go see them anyway, as they're not one of my favorite bands anymore, and I'd have to go to Copenhagen, which is in the other end of the country (4-5 hours by train) and that shit costs a lot of money!!!