The "Hands of God" rescue is great for righting a flipped kayak and still keeping the person in their boat.  Here is a video example: Hands of God Rescue.  In calm water, you can often empty their boat over yours, hold the boat upright to keep it steady so they can crawl back into the boat.  This is known as a T Rescue.  Here is a short video example: T Rescue.

Each craft has its set of advantages and challenges.  Decked boats like C-1's and kayaks are typically lighter and easier to perform T Rescues.  They are also quite tippy and hard to reenter in whitewater.  A raft is great for pulling a swimmer into the boat.  They are very stable and you can typically get several people to pull up on the swimmers PFD shoulder straps.  Canoes are a mix between kayaks and rafts.  They are not nearly as stable as a raft and lack the manpower but they are far more stable than a kayak.  You can definitely pull in a swimmer in calmer water into a canoe, it just take some bracing and team work.  T rescues are also easier on a canoe.

Swimmer stern tows are pretty straight forward, especially if you have a larger boat.  If you are being rescued, help out by kicking to provide extra propulsion.  Bow tows can be used when you have a distressed swimmer and you need to keep a very close eye on them.  A worse case scenario is rescuing an unconcious swimmer from a kayak.  Your number one objective is ensure they are face up and can breath.  Get help from shore or a larger craft like a raft ASAP.  Here is a short video on a boat based rescue of an unconcious swimmer.