I recently went Acer Aspire. No complaints. It handles everything the original poster mentioned. I have it running at 3 GB ram (if you want to exploit tis 4GB potential you have to use Vista or one of those wacky OS's that aren't fucked by Microsoft). I use it for video work on the go, and as a portable home theater PC. I used to own an HP and thought it sucked. I used it as the original poster did, often leaving it on for days at a time. It barely lasted two years. It did use a reliable Hitachi hard drive, which I recycled once the laptop shit the bed. In fact, I still use that hard drive, externally, to this day. To their credit, HP's customer service in America were actually pretty good, and its external case was solid and well designed. I do prefer this Acer over it. Before HP swallowed them whole, I used to own a Compaq and it was pretty well designed yet didn't survive two years. The HP had suspiciously similar issues.
I've had such a good experience with my Acer that I'm thinking about grabbing another laptop to use it exclusively for production and design work so I can use the ACER for what I had originally intended: as a portable home theater PC. I may go for another ACER, but MSI impressed me as well. My only problem was that the local computer shops only carried MSIs with INTEL chips. I wanted AMD. The various shop keepers were being total cunts and said they couldn't get me the AMD supporting models, which is China speak for the fact they were too lazy and couldn't be fucked to make a buck. Good on them because I took my hard-earned cash elsewhere. That's how I ended up on my path towards the ACER.
I must say, I would get a different model, though. I didn't get it for wireless service and I rarely ever run it from the battery. Its portability was important, but not in the "work wherever you are," sense that many laptop users require. I use it in a, "I can jack it into this YV, or that TV, or this projector, or that monitory" fashion. For internet work I simply plug it into the ADSL box. Having just arrived from holiday, I can say I wish I had wireless capabilities. I had some good time in a few airports and wished I had the ability to exploit their wifi, but did not have that ability.
I have wondered about the local brands. I heard Hassee had bad after-service, but they did have some decent pricing for loaded laptops, and their guts are not made from the bottom of the barrel hardware I would have thought. I haven't been able to get any solid opinions on Founder computers, either. No positive nor negative feedback, which is weird. My ability to read Hanzi is desperately poor, so I couldn't go online and chat with locals on BBS about the computer.
To be perfectly honest, I have never had a problem with Lenovo computers, and I actually like them, but I only use their desk tops. I have used some students' Lenovo laptops, and while they worked fine, I find them overpriced and pretty basic. Their desktops are at least explorer-friendly and I have juiced up, tinekered around with, and repaired a few for colleagues and students, unlike the proprietary screw shitboxes like Compaq.*
I hear Lenovo's after service is decent, but that is second-hand and not something I experienced myself.
* I ended up building my parents a new computer using some of the Compaq parts I salvaged (naemly: DVD drive, Western Digital hard drive, the ram and processor). It was hell on earth trying to get anything out of the machine because of the stupid, user-contemptuous, proprietary assembly of the machine.