Help me end my dependence on Comcast!

Hey folks. Semi-technology noob here. I'm in the North Bay of California, and am paying way too much for internet-only Comcast. I don't have cable TV (who needs it?), don't need their phone service, and I'm looking for alternate service providers. I'm in an small urban area and pretty sure there are one or two possibilities for another service. Are these companies hit or miss? Whose wires/connections do they use? My situation: 1 tv, 2 laptops (windows and mac), 2 phones and an xbox need connection, and to stream two devices at once. Small, one bedroom apartment, not more than 50 feet range from the co-ax cord. My questions relate to hardware and technology: How much internet download do I need (I've got what comcast says you need for streaming, but it struggles if the TV and lappy are going at the same time)? Why does my signal suck so bad in a teeny apartment (I'm renting the modem/router from comcast)? In the past(3-7 years ago), alternate service providers were crappy, almost as slow as dialup, and not much cheaper than the bigguns. Has this changed? Or is the monopoly going strong? After using a relatives, I was very impressed with Apple's Airport Extreme, is there a good modem to pair with this? Have those gotten more reliable recently too? Any other suggestions? I hope and wish that there was a solution. If someone or company could just have kick-ass internet with few problems and reasonable customer service, they would make a killing here. Thanks in advance for any advice, I do appreciate, cheers!