remote access software

[Linda]

I was wondering what list users would recommend for remote 
access via internet of a computer that does not have a 
static IP addresses. I noticed looking around that both 
TeamViewer and LogMeIn  support Linux. Looking for away to 
do the equivalant of ssh and ssh -X in a mixed compter 
environment where the client accessing the remote server 
could be either Ubuntu 12.04 LTS, Windows 7 or possibly an 
ipad.  Any recommendations or cavets would be greatly 
appreciated. Now that I have modem access working for all 
necessary functions I'm thinking about moving into the 
modern world and setting up something that would allow 
graphical remote use at a workable speed so I'm not tied to 
text based solutions.
                Thanks
                  Linda