Spawn a TTY shell

Often during pen tests you may obtain a shell without having tty, yet wish to interact further with the system. Here are some commands which will allow you to spawn a tty shell. Obviously some of this will depend on the system environment and installed packages.
python -c 'import pty; pty.spawn("/bin/sh")'
echo os.system('/bin/bash')
/bin/sh -i
perl —e 'exec "/bin/sh";'
perl: exec "/bin/sh";
ruby: exec "/bin/sh"
lua: os.execute('/bin/sh')
(From within IRB)
exec "/bin/sh"
(From within vi)
(From within vi)
:set shell=/bin/bash:shell
(From within nmap)
Many of these will also allow you to escape jail shells. The top 3 would be my most successful in general for spawning from the command line.