- I went for the destroy the synthetics option first. It seemed like it was the only way I would get out alive (and I did, as in the end they showed Shep breathing).
- I got disappointed with the ending (big surprise). In the end the 3 choices are very similar: all the mass relays get destroyed, Joker and my love interest (in my case, Tali) show up in 'somewhere', Shepard dies (or does he?), etc. I felt like my choices throughout the game (including the previous ones) didn't make much of a difference in the end.
- I didn't like that they simply came up with a god-kid to deliver last-minute exposition to explain everything. Besides, Shep accepts everything waaaay to easily. Especially when the god-kid says that he made the reapers because "the creatures will always be at war with the creators (or something)", considering that I successfully made the QUARIANS BE AT PEACE WITH THE GETH! I mean, shouldn't that count?
- The war assets in the end didn't make much of a difference. I was expecting a 'happier' ending (or a better one), since I managed to unite the whole freaking galaxy, had 100% readiness, etc. Sure, maybe Shepard would have to make an ultimate sacrifice, but there could be at least some 'closure', like destroying the reapers and saving the mass relays, later showing each species helping each other to rebuild their homes, showing my love interest & friends mourning Shepard's grave... things like that.
- Plus, ME:2's most controversial choice, the "destroy the Collectors/let Cerberus take the base" choice, does not make much of an impact here. All I had was: "oh look, they have that Reaper thingy in their base. that will be a great war asset, which will add a few more points to our Crucible".
- Despite the ending's disappointment, I had a lot of fun with it. I loved the Quarians mission. To take back Rannoch, destroy the reaper, all that tension, Legion's sacrifice... it was intense, man.
- The multiplayer is quite fun too. I think it was pretty clever to make the MP progress have some effect on singleplayer (I just expected a little more).
/my2cents