Let's ignore used laptops for now... Feel free to compare any of these laptops that I'm planning to buy very soon after I trade in my Mac.

Current laptop: MacBook Air (11", mid-2011)
Intel Core i5-2467M (dual-core with HT, 1.6 GHz, up to 2.3 GHz, ULV, 3M cache)
Intel HD Graphics 3000
4 GB RAM
128 GB SSD
No optical drive
8 months left in warranty

Maximum trade-in value: SGD 700


Toshiba Satellite L840-1027X
Intel Core i5-3210M (dual-core with HT, 2.5 GHz, up to 3.1 GHz, standard voltage, 3M cache)
AMD Radeon HD 7670M /w 2 GB of video RAM
8 GB RAM
750 GB HDD /w shock absorbers
DVD Super-Multi
Bluetooth 4.0
Comes with a 1-year subscription of Norton Internet Security
2-year warranty

Price: SGD 999

Acer Aspire V3-571G-73614G75Ma
Intel Core i7-3610QM (quad-core with HT, 2.3 GHz, up to 3.3 GHz, standard voltage, 6M cache)
NVIDIA GeForce GT 640M /w 2GB of video RAM (hard to believe, but this is faster than a NVIDIA GeForce 9800 GTX+! 4 years is a lot in the tech world...)
4 GB RAM
750 GB HDD
DVD Super-Multi
Bluetooth 4.0
1-year warranty
Possibly shoddy build as tested (!)

Price: SGD 999

HP Pavilion g4-2009TX
Intel Core i5-3210M (dual-core with HT, 2.5 GHz, up to 3.1 GHz, standard voltage, 3M cache)
AMD Radeon HD 7670M /w 1 GB of video RAM
8 GB RAM
640 GB HDD
DVD Super-Multi
Bluetooth 4.0
Comes with a copy of Trend Micro Titanium Internet Security (unknown sub period)
Warranty covers accidental damage, theft, and flooding/fire/lighting
1-year warranty

Price: SGD 899

HP Pavilion g4-2002TX
Intel Core i7-3612QM (quad-core with HT, 2.1 GHz, up to 3.1 GHz, standard voltage, 6M cache)
AMD Radeon HD 7670M /w 2 GB of video RAM
4 GB RAM
750 GB HDD
DVD Super-Multi
Bluetooth 4.0
Comes with a copy of Trend Micro Titanium Internet Security (unknown sub period)
Warranty covers accidental damage, theft, and flooding/fire/lighting
1-year warranty

Price: SGD 999

Lenovo G480
Intel Core i5-3210M (dual-core with HT, 2.5 GHz, up to 3.1 GHz, standard voltage, 3M cache)
NVIDIA GeForce GT 630M /w 2GB of video RAM
8 GB RAM
500 GB HDD
DVD Super-Multi
Bluetooth 4.0
Comes with 3-year subscription of McAfee Antivirus
$0 Windows 8 Pro upgrade on request
1-year warranty

Price: SGD 899

Some notes after having a hands-on on most of the laptops listed:

• All these laptops seem to have the same maximum brightness when it comes to their screens, but the Acer's screen is undersaturated and yellow-ish compared to others. The Toshiba has some vertical striping pattern on the whole screen which is usually unnoticable. The HP's screen's whites are perfect.
• The Acer trackpad tracks rather poorly with sharp acceleration drop-off. The HP trackpad works well, but has a very rough surface. The Toshiba trackpad is what I feel at home the most - despite it not being clicky, the trackpad is very friendly to gestures and responsive, with a silky-smooth surface.
• All these laptops are rather hefty. Don't even think about holding it with just one hand.
• All of these laptops have keyboards that work equally well. The Acer has a numeric keypad.
• All these laptops have switchable graphics. They all default to using Intel HD Graphics 4000 while not gaming, which is still faster than the HD Graphics 3000. The GeForces and Radeons kick in once you get into games, for a world of awesome. Checking out NotebookCheck reveals that they should be able to handle modern games at around medium or high settings, even games that are released as recently as yesterday! Some even get maxxed out!
• The Toshiba and HP are very colourful.
• All but the HP and Lenovo come with 750 GB of space. The Toshiba's hard disk is shock-proof. Makes sense for me - I drop things all the time.
• All the laptops are rather sturdy, but I don't trust Acer or HP, not with negative feedback.
• The Toshiba flies off shelves! Do people really like it?