You should get them, they're great
Also, to prolong the list here are some more names: Archon, AdoM (+ angband, nethack etc), Dungeon keeper, Total annihilation, starcraft.
Also, dom I PPP with the so lovely feature of maps actually changing to reflect your spreading dominion - It's really nice to see your cold dominion creeping over ever larger stretches of the map
And Lords of Magic is worth another mention as it has a nice "groove" to it.
krpeters & Executor, I think your explanation makes sense. It seems I share your point of view.
thejeff, if it's 90% crap then where are the 10% quality games?- Please, please point me to a good FTBS made lately. Or let's raise the bar, to a good FTBS made by a big company lately.
Zeldor, there's an extra value to the playing an innovative game for the first time. It doesn't have to be perfect or polished but it would leave a lasting impression - like reading a great book with a twisting plot. It gets worst when the sequel is dumbed down or more buggy than the predecessor.