So. My wife and I will be going to Tokyo, Kyoto and Osaka in May and we're looking to pick up a bunch of figures and gunpla. To the extent that we paid to have an extra bag on the flight home :p
Any good places to recommend for new and used? Would be looking for a nice selection and/or a good price :)
Everyone's already given quite a lot of good tips.
In Akihabara, AmiAmi actually has two stores now. One in the famous and prominently located Radio Kaikan building, but they also have their original location a few blocks away with 2 more floors of stuff. It's next to the "Akiba Culture Zone" building, and you can see the AmiAmi signs in the 3rd and 4th floor windows. Another good Akiba resource that hasn't been mentioned yet is Surugaya Specialty Store. They were just a bit player in Akiba the last time I was there, but they've expanded to multiple new locations, most of which all have different themes (Gunpla, board games, etc.) Of course there are many Liberty shops all around the area, but the best is probably Liberty 8 that's far down the main strip towards Suehirocho subway station. For Gunpla, you can also do amazingly well at "mainstream" stores like Yodobashi Camera and Sofmap.
In Kyoto, there's not much. Basically all I found this time was a Lashinbang at Teramachi (where I, OMG OMG OMG found Phat Bayonetta for a ridiculous, but not
too ridiculous, price and bought her! I'll have pics later =D), and another Lashinbang in Avanti department store just south of Kyoto Station. There's one other Gunpla store somewhere along Shijo Dori (4th street), west of Teramachi a little, but that's about it.
Osaka, I'm not very familiar with, basically the couple of Mandarake locations there.
Good luck!