i haven't tried them, but i hear traynor ycv50 blues have a good clean channel, and a marshall-y overdrive channel (from what I hear!)- you may be able to scoop that (only a little, megadeth aren't really scooped at all!) to get a megadeth-y tone. Also, since this is purely from hearsay, so when people say "marshall-y", they may mean vintage marshall, which isn't really what you want.
Yeah, I don't like the sound of scooped mids. I was originally planning on getting a Peavey Classic 30, or a Fender Blues Junior, and putting my Boss Metal Zone in front of it; however, I decided to just go for an all-tube amp with the distorted tones I'm looking for, as it would just sound better and more organic.
failing that, I second ben/twilight odyssey. if you can get more cash to get a better amp, you'll thank yourself later.
A Peavey XXX Super 40 isn't good enough? :?: :?: I've heard they're similar to 5150's, but not as dark.
I don't want to save forever - I have a very limited income (limited being $10 a week, and however much my parents decide to give me for my birthday, Christmas, etc), and I don't want to wait forever to upgrade my amp, because eventually I want to get an RG1570 with BKs in it as my next guitar, which will cost me about $1100...I don't want to spend much more than $600-$700 for an amp because, although the ones I really want to try/probably buy are far beyond that (ENGL Powerball/Savage, anyone?), there are ones I'm far more likely to enjoy for a long time without spending so much, like the aforementioned JCM800, the XXX, the 5150, etc. (just as examples).
I'm basically looking for an amp that will last me a long time and sound great, while being relatively cheap. I've noticed there are a lot of amps that are just plain overpriced (particularly halfstacks...a Peavey XXX Super 40 combo new is around $850; the 120w head alone is $1150, and each of the cabs is an additional $600 - is there anyone out there who actually needs a 120 watt all-tube fullstack?)
EDIT: ooh, if the price can't increase, how much can you get a randall rg50tc (haven't tried it, but again from hearsay, it might do what you want) or an ashdown fallen angel (have tried, I wouldn't recommend it if you can get more cash, but it's decent to good for the money, maybe a little modern-sounding though). Just another two to look into.
I recently saw the Ashdown Fallen Angel in a music catalog I got (American Musical Supply, I believe), and it looked okay, albeit a bit expensive. How are the all-tube Randalls? I've never seen an all-tube Randall; has anyone had any experience with them?
Oh, and on two different notes:
1) Does anyone know if Marshall still makes JMPs?
2) Are there 7-string versions of RG1570s? I've seen several guitarists I like use them, such as Steve Vai and Michael Romeo, and I like the extended range of the instrument and the chunky rhythm sound attained by that bottom string while not having to downtune.