Well, i started with ubuntu ages ago, before this computer had internet at all, i found it very hard, especially when installing new programs was concerned, as i had to download the source elsewhere and compile it etc.
Now i have the internet, it is very easy to get programs and updates etc. I decided to have another go as a project for the summer holidays. A big thing that made me do this was the discovery of "ndiswrapper," a program that lets you use windows wireless drivers, giving me the internet access. I got it going with the ATi binary drivers, Xgl and Compiz, which made it very visually appealing. I then put IM and media players on, and found I could survive only on linux, for most things. As I researched that evening, and learnt new stuff, i found i needed XP less and less, and I only use it for, as i said, 3d modelling, photoshop and gaming really.
I would say go for it, give it another go. If you dont like it, delete the partition, and instead of formatting, pop the xp cd in, and go the the console, and "fix mbr" to get rid of GRUB. I would recommend ubuntu, as it is one of the easiest distros to pick up. Also, unless you have a friend that is very good at linux,
i dont recommend you trying things like Xgl straight away, untill you have got the hang of things.
EDIT: for the id games, and ut2004, do i need to buy linux versions, or will the normal discs install on both? Also, is gaming better on linux, as the OS uses alot less resources. OS + Xgl + Compiz with IM, Browser etc leaves me using only 220MB ram. try that on XP!
it never uses the 1GB swap partition i made.