hi i have a roland cube 60, but the gain and lead controls on it dont satisfy me.

i dont know if i should buy a pedal or processor pedal, or a new amp entirely.

An amp that sounds like : Atreyu (new album), Bullet for my valentine (the poison), taking back sunday ( Tell all your friends), As i lay dying ( new album)
What guitar do you have? That could be part of it, but they are modelling amps right? Try changing the present to Metal, or Metal stack, that might get you closer to what you want. And although i dont like scooping out mids, try it. Just turn the middle knob on the eq low, or off, and turn the treble and bass up rather high. Also if theres onboard fx on it, make sure those are off. Im not entirley sure, my friend has one but i dont remember much about it.

Only get a new amp if youre planning to perform at gigs/venues, in which case 60 watts of power wont be enough. Dont just get another 60 watt.