European Excursion

I need some more wonderful suggestions now that the hubs and I have narrowed down our Europe city choices. We've ended up having to push back the trip (we were going to go in December) to March but as a trade off we get to go for longer, so I'm still very excited! And now, for the unveiling of the cities (drum roll please): London, Munich, Rome, Barcelona, Paris and Dublin. We plan on spending 3-4 days in each city, except London, probably about 5 days there at least. So what did you do that you absolutely loved, what did you do that you wish you hadn't wasted your time with? Where to stay (again, cheap, but clean)? Where to shop and what to buy (I heard something about cheap jewelry, perhaps in Rome) ? How should we travel from city to city, plane or train? Just give me all the juicy details! From my last post, I already have some great info (thanks again guys!) that really helped us decide where to go, so we reallly appreciate that input! I know, this does seem ridiculously early to start planning all the nitty gritty details, but anyone who knows me won't be surprised. I'm the girl who packs two weeks before my vacation and then ends up having to unpack to get to something that I prematurely packed. Over-planning calms me. :)

Europe Here I Come (well, I will be coming, in about 8 months... oh, but I'll be there!)