[sarasi]

What is your budget? Also, Tokyo is a huge city with a very large "city centre" area (or you could look at it as having more than one city centre), so you might want to be a bit more specific- have you seen any areas you'd like to spend time in while doing research for this trip?

Shinjuku, Shibuya, Akihabara, Ueno? Actually the public transport system is great here so you can easily travel around the central area no matter where you stay, but there is no point in suggesting a hotel in Asakusa if you actually wanted to be somewhere like Roppongi.