Of all the three, contrary to a large percentage of posts, in terms of which one I'd choose to cancel, I'd go with Miami. That Horatio has gotten on my nerves every time and it turns Miami into a stillborn show, a great show that never took off to begin with. I don't know why but whenever Florida-themed shows come in, I get the heebie-jeebies.
Why couldn't they do a CSI-Milwaukee, a CSI-Seattle, or even a CSI-St. Louis? You know, get TV-Shows that focus on cities, and towns that are almost completely ignored by mainstream networks. Just saying...
In terms of which one is most likely to go, 'New York' is most likely. Even Miami's episode viewership on Sunday's has been higher than any of NY's Season 7 episodes as of late. Friday Night is indeed a Death Slot and many shows that are moved there die within a season of moving there.
The Vegas show could come much closer to ending after Marg Helgenberger leaves which will be very sad. To see Stella and Catherine now gone, it's truly the end of an era, at least to me, and a chasm that will be very hard to fill in.
Two of my favorite female characters in over 15 years now gone, it hurts my TV-Heart a lot.
To be honest, all three of these shows have run far longer than most shows ever could dream of and this franchise has been fantastic even as decay, and entropy are showing as of late. The audiences of 2010-11 are likely worlds away from the audience of 2000-01 and the latter's tastes are likely changing hence the dip in viewership of all three shows and their desire for something new.
This era of TV has been wonderful but it will be a while before some other show of this calibre arrives and keeps me loyal for many years on end. Who knows when and what the show will be.