I just wanted to share with you some of my favorite remote desktop sharing programs.
Crossloop Free, You can however hire someone from their site to fix your computer.
This is pretty cool, I have a profile on there http://www.crossloop.com/D4RK_4NG3L
I personally can help fix your computer remotely. This program makes an easy front end for vnc
TeamViewer Free For Personal use but Has Paid Options.
All the paid options are, however aimed towards businesses with decent budgets so don't expect to pick this program up for commercial use unless you have some capital lying around. This program is smooth, and very configurable, if you are using for personal use only make sure that are very careful to install it using that option.
Windows RDP Free
Although this works well, it is not nearly as user friendly as the other options. Also while you use this, other people cannot watch the computer, making it not a great tool to help someone, or teach them. Only to login remotely and do what you want to.
Log Me In Free Free For Personal use but Has Paid Options also
I have used this service for a while however Teamviewer provides some functionality for free that Log Me In charges for, So it really depends on what you are using it for, that determines which one fits for you.
Go2Meeting Not Free
Is a reasonably priced way to share you desktop and hold meetings. Aimed more at small businesses there are options for businesses of all sized. While they don't have a free option, there are always free trials and discounts that you can get.
In conclusion. There are many different programs out there, no one program being the best. I recommend that you look at and try each program yourself, and choose the one that works best for your skill level and situation.