Sold State Drives are still not yet the default hard drive in most less expensive PCs and laptops. While their prices is dropping many manufacturers charge a significant premium for an SSD drive.
The question is, are they worth the price? Consumer level SSD drives can be as much as 20 times as expensive per gigabyte as their old spindle drive counterparts. Most of the significant kinks have been worked out of this newer technology and are often far more reliable than their more mature competition - spindle drives. The speed gain is undeniable as a SSD computer can often boot in 1/5th the time as a nearly identical system with spindle drives and the apps load in a blink of the eye.
One advantage of SSD is that they shouldn't be as susceptible to damage from falls as spindle hard drives. With any drives, I recommend backing up often. Since spindle drives are very inexpensive per gigabyte I recommend backing up to an old spindle drive even if you have a really fast SSD drive.
Samsung and Intel makes some of the most recommended SSD drives for reliability and great speed.
SSDs on a laptop may usually don't need to be too large so a 500GB SSD would be fine for most people unless you need to keep a copy of your video and/or movie collection on your laptop.
On my computer I have my OS, documents, swap file and applications all installed on my SSD card but my movies and music are stored on much cheaper spindle drives where they run just fine. You may wish to combine technologies on your PC.
For most of my clients, I purchase a stock computer or laptop and replace the existing spindle drive with a Samsung SSD drive as the data migration tool makes moving the boot drive from the original spindle drive to a SSD quick and easy. I leave the old drive in the computer as a backup system.