I have not encounter any major stability problem with Tiger so far... and here's some basic experiences to share as a student:
[Spotlight]
As lazy as I am, spotlight saves my trouble of browsing through all my lecture notes and even PDF notes for the topic that I need for my assignments
With multiple practical work saved as the same filename under different lab folder, placing my mouse cursor on the search result (which will show more than one relevance) shows the source of each file, no more trial and error.
I like to keep my desktop neat, with spotlight I can keep my dock icons to 10 including the trash can while launching the rest, less used, applications thru spotlight. Think of it as a much better solution to Windows XP's top5/top10 recently opened programs at start button :P LOL
[Dashboard]
Weather is there for me before I leave home, it's crucial since I walk to Uni.
Online resources in a few clicks, Wikipedia & Dictionary is ever ready.
iCal Events to keep my informed on my assignment due dates and timetables.
Gmail checker constantly updates me with my inbox status.
*Haven't got time to explore the other 1000 widgets out there, but as I've said, it's basic and it serves me well already!*
[Safari RSS]
Bookmarking RSS enabled news/forum sites allows me to glance thru the headlines fast enough before my girlfriend starts yelling at me for reading too much news :P
That's all I can think of with Tiger on my Mac, it's nothing much but imagine without these features...