The Fender Bassbreaker. Get a 15 or a 30R, depending on what you need it for. That thing can do everything and had that "punch" down for great punk rock.
For me, I was always a Green Day fan. An interesting thing about Billie Joe, after Insomniac, is that he started turning down his distortion. In my opinion, his guitar tone got so much better. I love the sound of an overdriven P-90 that is not too heavily distorted. Of course, he plays through two JCM 800 heads, I believe. The bass breaker with a Les paul Jr or Special can get you pretty close.