Civ was an awesome game. I didn't own it personally, but played it quite much with my friends.
Civ2 was my first own Civ game. I still consider it to be the best of its time. When it came out, it was much better than 3, 4 or 5 when they came out. It is still one of the few games where every unit did actually work.
Civ3 I bought this one later, not when it was new. I liked it.
Civ5 It is an mediocre game. It doesn't have soul like 2 and 4. It seems more like an console game, but slower. I just wait when it starts to support Wiimote, maybe next patch? I can grow into it, like I did in Civ4... but that doesn't seem very likely.
That was similar to my story! I still remember the "decoder disk" you had to use when you started up the game. What I wouldn't do to complete my collection and own Civ 1......
I have liked every game in the series so far, Even Revolution and Colonization. Every game brought something new and interesting to the table. I haven't had the chance to play 3 very much, but seems good to me

I have to disagree with your opinion of 5 though. I think it's a great game out of the box. It has it's issues sure, but it's all there. I also think it's just a matter of perception that you don't think the updates will improve your opinion of the game. The updates will come, and just like the update and expansions did for your opinion of 4, so will the updates and expansions of 5.