Good subwoofers for 2002 Honda Civic?

I'm looking into buying subwoofers for my Honda Civic and honestly i'm lost. I need a good brand and all the other essentials. Like a good size woofer a good size case to put it all that stuff. And maybe a good radio head.

There are hundreds of good choices but you don't even know what questions to ask or what information to provide, such as…

What is your budget? $200? $500? $1000?

What type of music do you listen to mostly?

What year and model Civic do you own? They aren't all equipped with the same alternator which limits how much amplifier power it can support.

Do you also want to amplify your other speakers and upgrade them for better sound? Before getting a sub, you should probably upgrade the door / shelf speakers first.