i am playing through a roland microcube since i am a beginner
i play anything i can get tabs on
i like rock and metal
what kind of amp should i be upgrading to?
MM Stingray
MIA P Bass
MIM Jazz Bass
GK 700RB-II Head
GK 410SBX Cab
Sansamp 3 Ch. DI
Crybaby Bass Wah
Bass Big Muff
DD3 Delay

MIA Strat
Nashville Tele
Martin 00015M
Hot Rod Deluxe
Big Muff
Hendrix Crybaby Wah
the more details you provide us, the more helpful our suggestions will be

What genre do you play mostly?
How long do you plan to stay with this amp? (If you will want an even better amp in a year, you'll probably be best to just save up and wait or something).
What guitar do you have?
What pedals do you have?
For the 300 dollar range, blackheart are a relatively newish company (i think), but apparently are very good

Im having a harder time with the 600 dollar range (for some odd reason) but ive come up with this:
SG commando

Inserts hilarious quote here
i like metal and rock, but everything else too
i have a epi lp standard plus top
no pedals
i plan to stick with the amp for a while

thanks for advice guys