Can consider these:
15.6"
Asus A550CC-XX530H, i5-3337U + Nvidia GT720M@RM2099[2kg], 4GB, 750GB, W8; colors: black/red/white

Dell
Inspiron 15R, i3-4010U + Intel HD4400@RM1599 [2.32kg], 4GB, 500GB(5400rpm), W8 , 6 cell
Inspiron 15, i5-3337U + AMD HD7670M@RM1749[2.25kg], 4GB, 750GB(5400rpm), 4-cell, Linux; W8SL@RM1899
Inspiron 15, i5-3337U + AMD HD7670M@RM1799[2.25kg], 4GB, 500GB(5400rpm), 6-cell, Linux; W8SL@RM1949

Toshiba
Satellite L50-A100X/XW, i5-3230M + Nvidia GT740M@RM2199[Onkyo], 4GB, 750GB, W8SL; 3 years local warranty; colors:silver/white

*Prices in RRP, negotiable
All these are budget-line notebooks, so can't really expect super good video and sound quality.
I suppose you could opt for Dell, and top up a bit to get 3 years on-site warranty service (best in Malaysia, fix any problems within 1-2 working days); or you could just get the Toshiba which comes with 3 years warranty (carry-in warranty though, do take note) 

Intel has the upper hand now
For a budget of RM2.5k, you can either consider this:
15.6"
Asus S550CB-CJ102H i5-3337U + Nvidia GT740M + 24GB mSATA + 500GB + (1366x768; touch)@RM2499[1.83kg], 4GB, W8
Or the ones recommended earlier, but use the remaining budget to get a full SSD (~RM300 for 128GB; ~RM600 for 256GB) to replace the original HDD that comes with the notebook. That way the speed will be a hell lot faster

Yeah, its pretty good, nice looking as well.
But do take note that Asus Malaysia's warranty service is one of the worst.
So 100% sure that you are getting a good unit before you go home after purchase   

Read here for more details, and you will understand why we say that https://forum.lowyat.net/topic/2337458
Yes, Dell offers the best warranty support (when covered, so its best to extend the warranty to 3 years).

These actually these 2 awesome notebooks from Dell as well, but since they have pretty weak wifi cards (short range), I don't really dare recommending them to you:
15.6"
Dell
Vostro 5560, i3-3120M + Nvidia GT630M@RM2009[2.2kg], 4GB, 500GB(5400rpm), W8, ODD
Vostro 5560, i5-3230M + Nvidia GT630M@RM2349[2.2kg], 4GB, 750GB(5400rpm), W8, ODD

The 14" version of this notebook has already been refresh. I suppose its just a matter of time before the new 5760 will be out with a better WiFi card, can wait for that if you want

Otherwise, just stick to the ones recommended to you, and slap in an SSD if you are feeling adventurous 

Your Asus can probably be "fixed" by getting a new HDD or SSD to replace the aged one
But since it is a 4 year old notebook, usually its best to just get a new one as you never know which hardware might spoil even after you replace the original harddisk

Can consider this for your budget:
15.6"
Lenovo
Flex 15, i7-4500U + Nvidia GT720M + (1366x768; touch) + 8GB SSGD + 500GB HDD@RM2699, 4GB, W8

Heard the speakers are very good
Otherwise these:
15.6"
Asus A550CC-XX530H, i5-3337U + Nvidia GT720M@RM2099[2kg], 4GB, 750GB, W8; colors: black/red/white

Dell Inspiron 15, i3-3217U + AMD HD7670M@RM1499[2.25kg], 4GB, 500GB(5400rpm), 6-cell, Linux; W8SL@RM1699
Toshiba Satellite L50-A100X/XW, i5-3230M + Nvidia GT740M@RM2199[Onkyo], 4GB, 750GB, W8SL; 3 years local warranty; colors:silver/white

*Prices in RRP, negotiable
*Macs are out of your budget unfortunately