In addition to poring over our reviews and checking out the vendors' sites, using the price filters at a reseller like Newegg.com can help you see different configurations at different price points. Some manufacturers offer lots of differently weighted versions of the same laptop (say, more storage in one config, a better GPU in another). Playing with the filters on these sites can be an illuminating exercise in give-and-take.
G-Sync or FreeSync: Several gaming laptops come with panels that support Nvidia's G-Sync or AMD's FreeSync technologies, both of which are designed to eliminate unsightly graphical tears and ghosting 0n monitors ranging from 1080p to 4K. While 60Hz is the current minimum refresh rate, there are an increasing number of monitors that offer 120Hz, which offers even faster rendering without introducing stutter.
Another spec to watch for is panel type. You'll want to go for an in-plane switching (IPS) panel if possible, as they generally offer the best off-center viewing angles and colors. Some gamers are content with cheaper twisted nematic (TN) panels, which make you settle for narrower viewing angles—but then, you're probably seated directly in front of the screen, so that's not an issue. TN panels can offer slightly faster response times.