Accomodations:
I quite like staying in Ikebukuro, it's not that expensive, the station itself is pretty close to places of attraction like Shinjuku, Shibuya, etc, and Sunshine City is not only a huge ass complex (more akin to American style malls so you might find it more comforting), but all around it there's stuff for the otaku to look at: There's an animate, k-books, manga no mori etc all close by. 2 places I've stayed at before are:
Kimi Ryokan:
http://www.kimi-ryokan.jp/
and House Ikebukuro:
http://www.housejp.com.tw/
Although the latter might only speak Mandarin Chinese as opposed to Cantonese (You do speak Cantonese, right?)
Akihabara:
The stuff that Gun has on there is still pretty much there, if I were to add anything it would be:
The huge Sega arcade is good for checking out the latest stuff, but if you actually want to play with others (and aren't afraid of getting your arse kicked) walk further down a bit to the Taito HEY arcade. Fighters are on the 3rd floor, and while KOF has never been as popular in Japan as say Guilty Gear, you'll find the 98 machines almost constantly occupied.
If you want cheap otaku goods, the building with K-books right as you come out of it is a good start - there's been a whole swarm of anime figurine shops opening up in that building. Also, if you're feeling more adventurous, try seeking out some of the Liberty stores - there's no English at all if I recall, but there's a huge catalogue of 2nd hand goods, and the prices are normally pretty damn competitive.
As an aside, I recommend Harajuku on Sunday morning/afternoon - there's always a large crowd of cosplayers around the station, Meiji Jinguu is a beautiful place and provides a nice, serene contrast to the chaos and madness of the cosplayers and the walk down Takeshita Dori.