Damn, just finished this series and i gotta say, it was awesome. I didn't realize who archer was while watching the series. I guess it does make a lot of sense now that I've read most of the comments here and the whole wikipedia article on him. As for it being obvious, a lot of it could have been attributed to coincidence ...###

scratch that i just looked back at how he got his weapons and it should have been apparent (at least a few episodes later that is). He uses the EXACT same method that shiro uses and we know that Servants, nor anyone else we know of, are not supposed to be able to do that. Furthermore, he uses a Reality Marble something which it said only magicians were able to do (none of the Servants were magicians except Caster). His comment to Ilya shows that he has had prior knowledge of her character.

As for archers personality check out the wikipedia article - it explains it completely.

I'd have to say that this had the best ending out of all the anime's that i can recall. Normally there would have been a way for Shiro and Saber to be together which would have been extremely corny. I especially liked how they showed his thoughts at the end where he wanted to be with her but knew that it was ultimately the wrong thing to do. I guess it shows him getting over the selfish quality of his that prevailed throughout the anime of wanting to be with Saber no matter what. This is also evident in the way (his explanation) of how he will deal with her loss. The ending's lyrics make sense when compared to the overall feel of the anime and the mood created by the last few minutes, however, i do not think that the music should have been so cheery. It kinda downplayed and contradicted everything that had happened in that last episode.

I also think that knowing Shiro's future (from wikipedia) made it all the better. Knowing that he would finally realize that his ideal wasn't all the he thought it was (not that I'm being sadistic, but it was an ideal that could only realistically lead to that painful discovery) makes it more realistic and therefore better, even if it is only in my eyes.