He Said, She Said

One of the hallmarks of an amateur is the way they handle dialogue. They can't believe that "said" is enough, and they have their characters blurting, exclaiming, postulating, and retorting. If you've done your job right and given your readers well defined characters and believable things to say, you shouldn't need to tell the reader HOW the line was said. When a woman walks in on her husband having an affair, we don't have to be told how she delivers the line, "How could you?"
Some writers feel they get into a rut using "said" all the time. This happens for two reasons. One, they don't realize that "said" is a great little word we don't mind seeing frequently. The other is that they don't know how to show which person is speaking any other way than to keep repeating, "Joe said" then "Sam said," then "Joe said" again. First of all, when only two people are speaking, it's often obvious whose line it is, and you don't have to spell it out. Also, you can establish the speaker by using action. Here's an example of both:
Joe turned back. "You coming with us?"
Sam looked up from the television, then back to the show. "I don't think so."
Joe threw his jacket across the leather wingback. "You never go anywhere. You can't just stay here like a hermit."
"I go places."
"The mailbox doesn't count."
Sam clicked the remote. "I like it here."
"Whatever." Joe grabbed his jacket and headed out.
See how the dialogue flows without anyone having to retort or exclaim? And you know who's speaking because you're describing their actions. Mentally immerse yourself in the scene and you'll see what they're doing. Then describe it and the question of who's speaking will answer itself.