Hello there!
i have a problem witn metasploit i dont wich of payloads is best for my exploit ( i know the server vulnerabilite and i sure about my expliot )and when i use "show payloads" command i see a lot of compatible payloads please help me to find the best payload

Try each one and see which works best for you! That's part of the fun of Metasploit. For each one that doesn't work try to find out why!

Steve

oh steve are you kiding!! it has hundred compatible payload and it takes a lot of time for me

On Windows, a meterpreter is always better because all windows post modules support it (plus tons of features).  It also communicates in SSL, so that adds a bit more stealth.  On Linux though, it's a different story, honestly you're probably better off with a non-meterpreter shell, because the Linux meterpreter isn't as good as the windows one.

reverse vs bind... come to think about it, I almost never use bind these days on a machine behind a firewall.  But people do use bind shells.

By the way, when you select an exploit, and do "show payloads" -- that will only show all the payloads compatible with that particular exploit.  If you're testing a web app exploit, keep in mind php/exec might not return an output (even though the command ran successfully).

If you're still clueless about which payload to use, just use a reverse meterpreter like everybody else has been recommending.

Lastly, perhaps you should consider asking Metasploit questions on #metasploit in freenode, so the actual metasploit dev team can answer your questions more quickly.

And yes... I did sign up for an account here just to answer your question.

btw you can use search commend to get selected exploits , like "search smb" . try it and lemme know