i use 2 or 3 actually.
logmein gets installed on every pc i make or work on regularly. i love how i can open up the webpage control panel and see 15 different rigs and even do windows updates right from there.
then, for my computers at home, i also install RealVNC. just a basic vnc program that works well. i use this because its much faster to login and start using then logmein is (no web based anything, its all direct connect).
finally, if i need to remote connect to a pc that i havent worked on before and im not at the location (can you help me fix my computer from 100 miles away over the phone?). teamviewer is nice because it requires no install or setup. just run it and have the idiot repeat the login number and passcode to me. bam, im in. then the first thing i do is setup and install logmein into that pc just in case i have to restart it.
honestly wish i could find one program that would tie all my needs into one, but i simply havent. i wish logmein would have sudo-clients or whatever you would call them... or just a way that i could directly, quickly connect to my lan computers.