Just noticed this thread.
In no specific order of preference:
* For PJ people, I guess you can count on Jason aka Djinn. To the uninitiated, his shop's located at Cineleisure @ Mutiara Damansara (Gamer's Hideout). Trustworthy and knowledgable. Do some search and you'll get more info - he's all over this forum

* The journey to Imbi Plaza's all worth it, to get your wares from Andy @ TNL (The Next Level). Like Djinn, his boss stocks the latest consoles & games, and does pre-orders too. Andy's knowledgable and trustworthy as well. As for me, I'd stay away from Connie the Conniving Witch @ Imbi Mario Trading (the shop opposite). Although they're of the same parent company, I've seen her work her wily ways against Andy many times before my eyes. What can be lower than taking advantage or stealing from the handicapped? She's dumb in regards to product knowledge. Plus, her customer service sucks and I can't take-in her fakeness. All $he want$ is your...
* In Sg Wang, I'd stay away from ElvenTech people too. They are Raymond (the round guy with glasses) and his PMS-24/7 wife, Alice. Me & my friends call her 'Unknown', after Tekken Tag Tournament's final boss - but that's just us. They LOVE to bad-mouth other competitors. They insult their less-knowledgable customers' intelligence by giving bull answers and deceiving them ("...the shop you went to is bluffing you! Unlike ours, their modchip will only last for only a year! Don't regret if you buy from them!"). Their warranty promises are mostly fat-fetched lies. They get most of their money by selling pirated games in bulk to overseas contacts, so they don't care much for walk-in customers like me and you. Oh yeah, right after they were forced to vacate their old premises due to being boycotted by neighbouring tenants eg. getting their entrance shutters & door locks stuffed with glue (in between getting lawyer letters from Sony), they resurfaced in Sg Wang by opening a certain official-looking (but not) XBOX-themed shop.
* In Sg Wang, on the 6th floor same as Red Box there's a shop (forgot the name) around the BB-Tea area (formerly RBT). Same parent company as TNL's, and there's a cool dude named Freddy. I get my fresh stocks from him & he charges reasonably. Knows his stuff well, and customer service is excellent. Gets straight to the point unlike the other sellers in Sg Wang, all meddling with their calculators as if they're working out a mathematical cure for cancer. More importantly, he's the person Connie from Imbi-Mario Trading sends all her customers' stuff to get repaired/modded (she will NEVER reveal his name or location, for obvious business purposes - she'll just tell customers she'll send it to her 'HQ'. Andy The Noble, on the other hand, will sometimes redirect his customers directly to Freddy - regarding mods/repairs/roms). Plus, Connie is fugly.
As a general rule of thumb, the cheapest is not necessary always the best. I will always go to the most knowledgable, most-get-to-the-point, most-respecting and LEAST-sarcastic salesman. Someone who doesn't treat or make me feel like an idiot just because they have goods that Sony, Microsoft or Nintendo doesn't want us Malaysians to have, and those grey-importers have them in stock. Plus, games salesmen (with the exception of Jason, Andy and Freddy) are always capitalising on the thrifty-shopper's pockets. They will almost always quote you the lowest price to gain your ATTENTION first, garnering your INTEREST, prompting you with a need to make a DECISION as your interest-level has peaked, then finally before your ACTION (taking out your cash/cc) they throw in the greed-bomb and start to quote necessary items (locally-compatible adapters, memory cards, controllers, etc) to ADD-IN to the final equation!
Just my thoughts. Raymond, if you're reading this, remember - you can run but you can't hide (Sony).