Edinburgh was my clear first choice.
Fairly early on into my undergraduate degree in physics in Dublin, I decided I wanted to pursue a research-based further degree in astronomy. After visiting several astronomy departments around the UK, a PhD at the Institute for Astronomy (IfA) in Edinburgh was my clear first choice as this offered me both an excellent academic environment together with a great city to live in. Luckily they offered me a place and since then I haven't looked back.
Given my interest in extragalactic astronomy and cosmology, Edinburgh was a natural choice for my PhD as it's home to some of the leading international researchers in the field. During my PhD, I had lots of opportunities to work with and learn from these scientists as well as others further afield through international collaborations.
In addition to being a first-rate academic institution, the IfA has a very friendly and relaxed atmosphere to work in. There's very little evidence of any hierarchy in the institute with academic staff, post-docs and students all mixing freely at lunch and coffee times. I found doing exciting scientific research within such a pleasant atmosphere to be a privilege and I fully enjoyed my post-graduate days here. So much so that when I finished my PhD, I decided to stay on at Edinburgh for a post-doc.
Edinburgh itself is a fantastic city to live in. Whatever your interests, there's always lots of things to do — there's great nightlife, theatre etc. and, of course, there's the festival(s) in August and Hogmany at New Year when the place goes completely barmy! And if you want to get away from it all, the spectacular Scottish highlands are just a short drive away.
All in all, I've found my time at Edinburgh to be extremely rewarding and can recommend it thoroughly for a PhD. But don't just take my word for it — come and visit and see for yourself!