Tough question. I haven't played Sacred, but I played Gothic 2 a lot. If your decision is stuck just between these two games, then choose what is more appropriate to your taste and current mood (yes, if you played isometric RPGs for last year then you probably may wish to try different genre for a while).
Sacred, as I have heard and it is written here is hack-n-slashish RPG.
Gothic is third person action RPG (please guys, I use these termins just to describe the game <img src="/ubbthreads/images/graemlins/winkwink.gif" alt="" />). Gothic has it world with it's critters. There are large and open ended areas full of quests and mystery. I liked the game and the atmosphere, which is quite unique in both Gothics.
As for other games, you have seen that there are several excellent games released lately.
My top priority for now is: Splinter Cell: Pandora Tomorrow (I loved the first game and will definitely buy this one, just have to wait until my video card gets fixed). There are also Far Cry and Unreal Tournament, two games that have very high ratings.
True, that we have hardly enough time and/or resources to play them all, so just choose what you like best. Hope this helps.
