The aptly named Sarcastic Gamer has been running a feature where they cover a great gaming moment each day. Number 62 in their top 100 is the gaming moment BioShock.
The style, action and gameplay was just too good. I didn't miss multi-player for a minute. In fact, if given the chance, I'd choose an excellent single player experience like BioShock over a mediocre (slapped-on) multi-player any day.They also note it's "breaking ground" as well as a "milestone", which apparently means that they never played System Shock 2 and don't realise it's all been done before (and better).
I'm looking at you OVERLORD.
Anyway, the (plasmid) abilities and cool weapon combinations allowed you to play the game differently every time. It was certainly a milestone in gaming creativity, and it's hopefully a sign of even greater things to come.