I am in Tokyo at the moment in the Shinjuku region, which contains two of Tokyo's best camera stores.
1. Yodabashi (lots of different stock, all camera's and many lenses (including L's) on display to touch and feel - expensive compared to Singapore!
www.yodabashi.co.jp
2. MapCamera (1 & 2). 1 is in the building next door to Yodabashi and 2 is in the next building along. (All three are located on the western side of Shijuku station, maybe 2 mins walk). 1 has all the used lenses (lvl 3) and 2 has all the new (lvl 3) and used bodies (lvl 2). You can find bargins for used lenses, e.g. 85 1.2L for under S$1700, but most are not that cheap and most include local warranty, 6 months I think (I don't speak Japanese and there's no one that speaks better then bad english). Used bodies are a little cheaper then in Singapore, but not by much (but they do have the warranty). Lot's of 1D & 1DMkII's, saw a used 5D for about S$3900, etc... No bargaining here!
New and used accessories, like flash units, etc are cheaper here then in Singapore.