So, you'd like some internet. Unfortunately, you are in the USA, so your options are limited. Fortunately, San Francisco has some pretty good options by American standards.

The Big Boys

Known for their terrible customer service, bandwidth caps, and general spinelessness, big ISPs offer reasonable speeds for reasonable prices. Sorta.

  • AT&T -- Offers fiber to the node/cabinet over DSL and fiber to the premises
  • Comcast -- Cable
  • Wave a.k.a. Astound -- Cable via a Hybric Fiber Coax network - Speeds up to 1,000 Megabit/1 Gigabit per second - Available in about 50% of SF residences
  • Wave G -- Only delivering in Multi-family properties (Apartments and Condos) - 1 Gigabit per second symmetrical delivered via the ethernet outlet in your unit

The Little Guys

  • Sonic.net -- Based in Santa Rosa (about 50mi north), sells symmetric 1Gbps and 10Gbps fiber to the premises. Formerly also resold different services over AT&T wires.  Better customer service than any of the big boys, and has a perfect score for respecting your privacy from the Electronic Frontier Foundation (an amazing digital rights advocacy nonprofit based right here).
  • MonkeyBrains -- Based in San Francisco, sells wireless point-to-point access in most neighborhoods.  In mid-size and large buildings, they do that same model as Webpass / Wave G and have 0.5 Gbps or 1Gbps service to units using in building Cat5 connected to fiber or microwave uplinks.

The other guys

  • Webpass provides insanely fast Internet (100-500Mbps) to residential units, but they require a building that's 1) built after 1995 2) has 20 or more units.  So, in other words, you've got to live in an expensive condo to get it. Figures that this would be the ISP that Google eventually acquired and later rebranded as "Google Fiber Webpass" everywhere.
  • Fastmetrics provides internet, phone, and data center services to businesses only. Fiber optic internet service up to 1Gbps up and down, plus list of pre-lit buildings. Service to the entire Bay Area. All internet services include unlimited data usage and IPs. Business broadband, ethernet and hosted phone service options. Routers, switches and / or softphones included with contracts. Locally based San Francisco support. 

Evaluating ISP performance

A great dataset for looking at ISP performance is this speedtest.net page.