Well... we could do ranked voting system, to pick them.
[Hider=Skip, if uninterested]
The higher the number the higher the ranking, like so:

8 Glasgow
7 Gumi
6 Belfast
5 Leeds
4 Geoje Island
3 Seoul
2 Dorset
1 Jeonju

The rank equals the number of votes. The 2 lowest ranked picks between the two of us are eliminated, and the votes for those two picks go to the highest two picks. Round two would only have 6 options to pick from, and the same voting rules apply. Rinse and repeat, until we have a clear majority winner. Ideally, this would be a lot faster, if we could meet on IM for even 2 minutes. xD [/hider]
Discussing the individual merits of each seems like it would get really tedious, more so than voting (since the math is painfully simple.)
But I can boil my own thoughts on the matter into as few words as possible
[hider=Like so:]
Glasgow - Personal bias, I have family and friends there.
Leeds - Seemed like a good idea.
Goeje Island - It's an island. <3
Gumi - Large enough to have economic growth, small enough to not be bursting at the seems and probably the feel of a smaller city.

Belfast & Dorset - I feel as strongly about these as I do Leeds. =P 
Seoul - I admit it has a "Rule of Cool" factor, but while I like cities, megalopolises whose individual districts are cities unto themselves, I'd like to avoid. 
Jeonju - While I've never heard of this place until now, it ranks about where Gumi does after a google search. [/hider]