There is one very specific thing that my browser must be able to do: restore my session (tabs and windows) upon browser quit/crash. It never ceases to amaze me, and moreso as the years march on, how few browsers actually have this ability. The only browsers I'm aware of that offer this natively are Opera (for Windows, Linux, and Mac OS X) and OmniWeb 5 for Mac OS X. That's it! I don't get it, but I digress as I've complained about this many, many times in the past and more of the same drivel now isn't going to change anything. It's apparent that the masses don't want, or rather, don't realize that they need, this option. Where I can't live without it, it seems that most don't even know to want it, but that goes back to my argument that 99% of the population seems to be apathetic to the fact that they're inefficient (which is fine *shrug*).
I've wanted to use Safari since it burst onto the scene, and for a very short time I did, but there was that nagging problem of not being able to restore my session when something went awry (you'd probably tell me "nagging problem" was too weak a description if you were sitting next to me and saw me lose all of my open tabs). Let there be no question, Safari is a great browser, but it couldn't do the one required task that I needed (it can now; read on).
There are a few solutions under Mac OS X, but most have deal-breaking disadvantages (at least for me).
OmniWeb 5, which I actually put in my Required OS X Programs list earlier this year, and which John Gruber wrote a great review for, probably has the best implementation of session restoration that I've ever seen. Hell, the browser itself is one of the best I've ever used, but I just couldn't bring myself to shell out $30 for it (a reasonable price, but with cheaper solutions available it went to the bottom of my list).
Another option for Mac OS X is Mozilla Firefox. I love Firefox and I have used it through all of its various versions and name changes since the very beginning many years ago. As you might have guessed, Firefox doesn't restore tabs, though through extensions the capability is there. For the last few months I've been forced to use Firefox v0.8 even though they have been releasing newer versions for a while (including the big 1.0!). The reason for this inability to upgrade is simple: the SessionSaver extension that restores tabs for Mac OS X will only work in Firefox ≤ v0.8. The extension is excellent and really does a great job, but I don't like the fact that I'm stuck in an "older" browser and I'm pretty sure that development has stopped entirely on the extension. Yes, there are other extensions that will do the same thing, but they don't work quite right in Mac OS X. Take Tabbrowser Extensions for example. This plugin is perfect if you are using Firefox in Windows, but it has never worked correctly in Mac OS X. I check every new version, but it's always the same story — "Last tabs don't reopen at next startup in Mac OS X" — this has been the case for at least a year.
Sick of being stuck in v0.8 of Firefox, I started to look for other solutions. I heard about various AppleScripts that could essentially do what I wanted within Safari, but these required manual save and restore actions on the part of the user. So, not only does it require the user to remember to save/restore at quit/shutdown, it does nothing for the user who accidently quits the browser or who's computer/browser crashes.
Another, ultimately equally useless option, is Safari Helper. While a decent program, it exists completely separate from Safari itself and requires the same manual interaction I was just talking about.
Despite the ostensible lack of solutions, there is actually one little program out there that does the trick. Saft for Safari is the best thing I've found for session restoration on Mac OS X, and it also offers quite a few other neat features to boot. I really put this "plugin" to the test before I actually bought it, and have yet to have a single problem with it — it handles tab/window restoration wonderfully. Notwithstanding the fact that I really don't use any of its other functions, I paid my $10 with no real trepidation because it does exactly what I need and has made Safari usable for me.