Which is the best solder type?

60/40 rosin core is good enough, but the best conducting solder that i know of is silver bearing solder, which is like 4% sliver.

What are you trying to solder?

I solder about everyday. I always use either Multicore 60/40 or Kester 44. Hands down the best I've used. Be sure you clean really well and match the solder size to what you are soldering.

If you are applying the flux yourself then a silver solder is great. If you are not applying the flux yourself then you will need a rosin core (60/40) type solder. Rosin core has the flux built in.

Rosin core solder is best for smaller (IMO) more delicate type of soldering such as circuit boards and RCA connectors. Silver solder you can purchase in a large diameter and is great for soldering larger projects like 1/0 copper lugs. You just have to apply the flux yourself. This is my opinion others like to use silver solder for everything and yet others like to use rosin core for everything.

I use rosin core solder whenever I use my soldering pen. I use silver solder whenever I use my torch.

Some people argue that silver solder has better conductivity but I am not concerned about details that insignificant.

edouble 101, I registered just so I could say thanks for the information. Your reply covered types of solder, the differences and when they should be used. Just great.

I just got a new car stereo and I am going to wire it up today.

Personally crimping rather than soldering is my favorite for two reasons, a mechanical connection will always be better than solder which uses tin and lead. Also if you do not support the solder from moving it will eventually crack because it is brittle. I only really solder when I have to, I usually use a hydraulic crimper or for smaller jobs but connectors.