#1
Ok, so like the title says. I'm buying a new amp, but I have no clue which would sound the best for me. I am a metal head... I usually play Metallica, Avenged Sevenfold, Pantera, etc... I'm using a Schecter Synyster Custom through a crappy 15 watt Crate right now. I need an amp that will be good for 3 things, live playing, recording, and practicing. Half stacks aren't really a good idea for me, because they would be a pain to get around, so I was thinking maybe a combo amp. My budget is $600. Thanks for all your help!
#7
Line 6 Flextone III. It's a nice amp, even though it's Solid State. Just because it uses the same technology as your Crate, it doesn't mean it will sound the same.
http://cgi.ebay.com/Line-6-Flextone-III-3-Combo-Amp-Excellent_W0QQitemZ350231518498QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item518b6cdd22&_trksid=p3286.c0.m14&_trkparms=65%3A12|66%3A2|39%3A1|72%3A2127|293%3A1|294%3A50

Peavey 6505 Combo. This isn't ideal for practising, but perfect for gigging.
http://cgi.ebay.com/Peavey-6505-212-Guitar-Combo-Amplifier-5150_W0QQitemZ300331600368QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item45ed2889f0&_trksid=p3286.c0.m14&_trkparms=65%3A12|66%3A2|39%3A1|72%3A2127|293%3A1|294%3A50

Marshal DSL. This isn't the best amp in your price range, but it's certainly worth considering.
http://cgi.ebay.com/2005-Marshall-JCM-2000-DSL-401_W0QQitemZ320401449864QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item4a996a2388&_trksid=p3286.c0.m14&_trkparms=65%3A3|66%3A4|39%3A1|293%3A1|294%3A200

Another Line 6 that some show disdain for, but only because of the word "Spider" in it's name tag. It's a nice amp.
http://cgi.ebay.com/Line-6-Spider-valve-112-amp-with-FBV-Shortboard_W0QQitemZ330346527229QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item4cea2ff9fd&_trksid=p3286.c0.m14&_trkparms=65%3A3%7C66%3A4%7C39%3A1%7C293%3A1%7C294%3A200

Peavey Vypyr Tube. This is a little fizzy and weak sounding, but worth a note.
http://cgi.ebay.com/PEAVEY-VYPYR-TUBE-60-GUITAR-AMP-WITH-SANPERA-I-NEW_W0QQitemZ140335621198QQcmdZViewItemQQptZLH_DefaultDomain_2?hash=item20aca7a44e&_trksid=p3286.c0.m14&_trkparms=65%3A3%7C66%3A4%7C39%3A1%7C293%3A1%7C294%3A200

Bugera 333XL. This is a Peavey JSX "clone". I haven't personally tried this version, but they are supposed to be quite good for the money. Some have had reliability issues with them, but that's generalizing.
http://cgi.ebay.com/BUGERA-333XL-NEW-CELESTION-SPEAKERS-JJ-TUBES-PEAVEY-JSX_W0QQitemZ320400911449QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item4a9961ec59&_trksid=p3286.c0.m14&_trkparms=65%3A3|66%3A4|39%3A1|293%3A1|294%3A200

Vox AD100VT. This seems a bit steep. Try and find a used one. They are not full-tube amplifiers, but still sound nice for classic rock.
http://cgi.ebay.com/Vox-Valvetronix-AD100VT-Guitar-Modeling-Amplifier-NEW_W0QQitemZ230359662188QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item35a2817e6c&_trksid=p3286.c0.m14&_trkparms=65%3A3|66%3A4|39%3A1|293%3A2|294%3A200

Peavey Valveking. Another decent amp. It has the potential to be better with the correct modifications. As it is, it still sounds fine, particularly with a pedal as it's overdriven tones.
http://cgi.ebay.com/2008-Peavey-ValveKing-2-12-Tube-Amp-IMMACULATE_W0QQitemZ250471553742QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item3a51449ace&_trksid=p3286.c0.m14&_trkparms=65%3A3|66%3A4|39%3A1|293%3A2|294%3A200

Peavey Triple. A nice amp. It seems very low in price. Check it's okay. This is the best amp for your money.
http://cgi.ebay.com/Peavey-XXX-Triple-X-Super-40-Tube-Amp-w-Footswitch_W0QQitemZ180388297567QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item29fffafb5f&_trksid=p3286.c0.m14&_trkparms=65%3A3%7C66%3A4%7C39%3A1%7C293%3A3%7C294%3A200

Also look out for a Randall RG-50TC and a Bugera 6262.
#8
Try a used Messa some dude got a triple rect for like $500 the other day!

Good Luck,Happy Hunting!

My Gig Rig...

Fender Straocaster or Gibson Les Paul Slash Special -->Lovepedal Amp 50 --> Boss DD-3 --> Crybaby(soon to be Wh10 reissue) --> Big Muff PI --> Boss DS-2 --> Marshall JCM 900
#10
I play Metal similar to the bands you like, Metallica, Avenged Sevenfold, Pantera, Megadeth and so on. And i recently bought a used Peavey 5150/6505 212 Combo, and its f***ing awsome. It will definitly satisfy you for Metal playing. Check it Out.
Although it is extremly heavy, so you might wan't to consider the upcoming 112 6505 Combo