Assassin's Creed or Bioshock (or both)?

I need help. I stumbled across a good promotion on the PS3 store. They are selling five Assassin's Creed games (I, II, III, Revelations and Brotherhood if I'm not mistaken) for 10 euros. It seems like a really good deal so I'm tempted to get them. For those who have played them, are they good? Are the story and characters interesting? Is the gameplay fun and engaging? I've being watching a lot reviews, gameplay videos and random parts of walkthroughs to get a better idea, but I'm not sure.

Alternatevely I could get the Bioshock trilogy for about 14. I still can't decide between these two (or if I should get both). :sweat:

Any opinion is welcome!

If you're a fan of horror-type games, the Bioshock games are probably a safe bet. I've only ever actually played Infinite myself, but the two preceding titles are widely acclaimed. The gameplay of Infinite didn't particularly stand out to me, and the story was surprisingly predictable considering it involved dimension-shifting and time travel shenanigans. Of the two main characters, Elizabeth is a lot more interesting than the playable protaganist. I primarily remember Infinite for its gorgeous flying steampunk city setting, which is reason enough on its own to play the game, in my opinion.

The Assassin's Creed franchise starts off with an okay game which feels more like a proof-of-concept than a finished product. The fighting and climbing/platforming gameplay is okay, but definitely gets more polished in future iterations. The fact that the story is split between the past and the present day is a bit of a fanbase-splitter, but I found it engaging. Characterisation in the first game is pretty weak, but improves a lot in subsequent entries. II improves upon the formula of the first game in every conceivable way, and is a pretty great game. Brotherhood and Revelations very much ride on II's coattails, spinning things out in an entertaining enough way, but not really bringing anything new. I'm a sucker for the setting of Istanbul/Constantinople in Revelations, though, it looks fantastic. III is the start of the AC Dark Period, which, depending on who you ask, has only recently ended with AC Origins. III isn't terrible, mind you, but it definitely felt like a step-down in quality in a lot of ways.

Thank you for the long and detailed reply.
I think tomorrow I'm going to try a couple of demos to see which games I enjoy the most, and then I'll make a choice. I'll let you know! ;)

Well, unfortunately there was no demo available to try these games out, and since I wasn't 100% convinced on both franchises eventually I got Tomb Raider and a couple of DLC for Mass Effect 2 :|