What do I do now? Electrical problems in my car.?

So I started having problems a few months ago with my car dying. First I replaced the battery and the alternator. Car seemed to be working fine. After about a month and a half my car started to die again. Something is killing the power in my car. I replaced the serpentine belt because I thought perhaps it was slipping on the alternator and was quite worn anyway. It is still dying. I think the next cheapest fix might be a bad ground. How do I check this? Other than that there is got to be a parasitic drain in the system somewhere. Whats the best way to diagnose that? Seriously, plugging my car into the charger every night so I can get to and from work is starting worry me about maybe ruining my battery and I'd like to get this fixed soon. PLEASE HELP.