Solid stainless pins, hands down. They simply don't break. Order 3/8" round stock from McMaster Car, cut to length, drill a hole in the end, and you're good to go at 1/2 the price of what Hobie or Murrays wants.
Your transoms will not be damaged by using stainless pins unless 1) you back down a wave launching in the surf or 2) your transom was going to break anyway.
Aluminum and plastic pins will all break, hollow stainless will bend. If you use nylon busings in the rudder castings, galvanic corrosion isn't an issue. I would never use anything besides stainless (even in the surf).
Last edited by srm; 09/20/12 10:47 AM.