Well, seeing most people here seems lazy to do some study on the phone available.
Let me help you all out thought, choose phone based on the processor will be the safest bet.
Ignore those battery life claim, due to bigger, higher res screen, and 4G network, all phone battery life sucks.
Be prepare to bring wall plug charger or power bank.
Speaking back to the processor, only choose phone with Qualcomm Snapdragon high end processor, such as S600, S800, S801, S805, S810 and S820.
Even though those S800 series has over heating issue, they offer the best performance in day to day use, and gaming as well.
Forget S615 and S400/S410, they are just as slow.
RAM count, no need so worry, 2GB RAM actually is enough, more RAM doesn't make the phone faster, just good for multi-tasking, but average user seldom multitasking, even the OS itself will close the program if not used for very long time.
After that, come to the budget and brand selection.
Want the most high end and reliable device? Only buy from Samsung, Sony, Apple, LG, HTC, Motorola.
Stay away from budget brand like Huawei, Lenovo, ASUS, Acer, Alcatel, Xiaomi, Oppo, Meizu, Oneplus, ZTE, Ninetology.
Those budget phone is very good in value, and feature high end processor, high end feature at very budget price, but the quality and reliability isn't there.
You may buy those phone in a risky situation where budget allowed, but when your phone got issue, the after sales service just isn't there. Recommend just buy from ASUS, if local warranty is your concern, at least ASUS still has very respectable local support.
No money to buy high end phone? A very good advise is, buy the phone from last year flagship, which has price drop near or similar to those offer from budget brand. The old flagship, starting from year 2013, featuring at least Snapdragon 600 processor, are still very good, almost no different in feature compare to those phone offer in year 2015. They are still pretty fast, fast enough for everyday usage without any weird issue.
Lastly, my recommendation as below:
Over RM2000 budget:
Samsung S6, S6 Edge, Note 4, Note Edge, HTC One M9, LG G4, Sony Xperia Z3,Z3+, iPhone 6/6 plus
Around RM2000 to RM1500
LG G3, HTC One M8, Desire Eye, Butterfly 2, Sony Xperia Z2/Z3 Compact, Samsung Galaxy Note 3, S5
Around RM1000 to RM1500
HTC One M7, Sony Xperia Z1, Samsung Galaxy S4, LG G2
For those budget minded and won't mind on the headache on after sale service, here are some phone with high end Snapdragon processor, but with much budget price tag.
Oppo N3, Oppo Find 7/7A, Vivo Xplay 3S, Vivo Xshot, Lenovo Z2 Pro, Oneplus One, Xiaomi Mi4, Mi3, Xiaomi Mi Note/ Note Pro, ASUS Padfone S/S Plus.
For starter, recommend ASUS Padfone S/S Plus, Xiaomi Mi4, which spot Snapdragon 801 processor with less than RM1000. Guarantee those phone is lag free in comparison.
Move up a bit,, over RM1000, but below RM1500 you do get Oneplus One, Vivo Xshot, Oppo Find 7A, Lenovo Z2 Pro, Sony Xperia Z1, Sony Xperia Z Ultra.
On the highest budget end, Samsung Galaxy S5, Galaxy Note 3, LG G3, HTC One M8, HTC Desire Eye, should be a pretty good buy. (Around RM1500++ to RM1700)
Stay away from other budget phone, especially those using Mediatek processor, and those from budget brand.
Beg to differ. I have Sony Z3 and your so called budget brand Huawei Mate 7. I experienced SOny aftersales service is very bad. On the other hand Huawei offers 1 to 1 exchg for the flagships(1 year !). Wat abt sony? I have to wait for almost 1 month for warranty claim eventho i used only for abt 2 weeks.
Not to mention Oppo warranty claim is darn fast compare to other manufacturers.
Its funny when you say Htc,LG,Motorola have better aftersales service. Their service centre barely cover the whole Malaysia,bro. If not mistaken only one or two in whole Malaysia. How is the reliability at thr? In fact.just to tell you,HTC offers one fo the worst after sales service in Malaysia.
Talk from experience ,bro. Dont simply fire up from nets.