I was using rdesktop until Ubuntu 12.04, then I started using Remmina because it is installed by default.
Remmina, is not as bug-free as rdesktop. The keyboard mappings get cross-wired sometimes in Remmina (it seems), and sometime characters in NotePad (on the remote server) get chopped of at the end (to where the characters are there but you can't see them).
However, the killer feature in Remmina (for me), is scaling. It allows me to magnify the remote desktop to a size my aging eyes appreciate.
Question: is there a program that does scaling, that is as solid as rdesktop, without the bugs of Remmina?