If you stick with Mac you may consider adding two things:
Parte the First: I do not remember if your version of Time Machine makes a "bootable" clone--one you can actually "boot up" the computer from. I believe the more recent for the Intel Macs--like OS 10.5+ do. The reason is IF your HD dies, you now have a dead computer until you get a new HD, put it in, reload the OS from your disk . . . then transfer yourself over. With a bootable clone you simply boot off the attached HD and use your computer until the new Int HD come in. You can then clone yourself to the new Int HD. If Time Machine you have does not do that you need to buy a program like SuperDuper!--which I have--or CarbonCopyCloner--one a few people here recommended. However, if you plan to get a "better" Mac that is Intel some time--or just use the Mac periodically--you may not wish to spend the $20-40 on that.
Parte the Second: Get DiskWarrior. This is a powerful volume fixer that has recovered damaged volumes that Disk Utility cannot. Now if you clone/back up that is not so much an issue, though I did have a problem happen before my daily cloning so my clones had the damage. Anyways, I had a HD failing--and they can fail like THAT BOOM!--and DW was able to make a disk image of my data--which I could then back up--before everything went to crapola.
Again, if you are just an occasional user, it may not be worth the $100 for that! If you do consider getting it, ask for a version that is "Universal"--will work Power PC and Intel so if you do upgrade your computer someday, you have a working version of DW. If you consider that a good idea I would suggest you get it now and check your volume to correct things Disk Utility may have missed.
Oh and rotate your tires. . . .
--J.D.