Imtra (Imtra.com) totally refurbished my 20-year old Muir Windlass after it stopped working. They did a great job and the price was very reasonable.
I think both Defender.com and Jamestowndistributors.com are great. I sometimes can't believe how fast I get my stuff with regular shipping (sometimes next day after ordering the previous night). Torrenson marine is good for Yanmar parts. Go2marine.com is good sometimes as well for parts.
After having a couple of dhingy lights rust or break on me, I purchased an all around light from Kayalite. It is worked wonderfully so far. (only about a year but longer than the others). It is not the completely stable on the back ledge of my dinghy but it doesn't ever fall off.
For wifi I bought from islandtimepc.com. The system has worked well and they were very helpful replacing a part.
When I needed someone to do some general work on my boat in Stuart FL, I used Damsel Marine. Carl did a really good job working on a variety of issues.