Wattage / Lumens
Some brands claim to replace a 40-watt or 60-watt incandescent bulb when in fact their light output is far less than what they claim to replace. So make sure to check the lumens (light output) of a bulb. A 40-watt replacement should produce around 450 lumens and a 60-watt replacement should produce around 800 lumens.
The second thing to consider on this topic is if a bulb does produce the right amount of lumens, how many watts does it take to do so? As of this writing, a quality LED bulb will typically take 9 to 11 watts of energy to produce 800 watts. Some cheaper bulbs require more energy, which means you're throwing away money over time. So the initial price tag doesn't tell you the whole story.
CRI stands for "Color Rendering Index" -- the higher the number (with a maximum of 100), the more accurately a bulb will render colors. Most LED bulbs are around 80, but some cheaper LEDs won't tell you their CRI, and this could be a red flag. (Some more expensive LEDs could also have higher CRIs for color critical applications.)
On the topic of color, bulbs come in a variety of "color temperatures," measured in degrees Kelvin. Most household applications use bulbs with 2700K to 3000K -- these are called "warm white" (with 3000K being a little "cooler" than 2700K). Office settings often have cooler or whiter color temperatures of 3500K or 4100K. (And bulbs can be even cooler than that.)
Cheap LED bulbs often don't have color consistency, so while a set of them might sell as 2700K (for example), they might look a little different from one another. Either that, or their color temperature may change over time, so if you have to replace one bulb in a couple of years, it might look different than the others.
By purchasing a known brand, you have a better chance for enjoying a consistent color temperature between the many bulbs in your home or office.
Most light bulbs are not set on dimmer switches, and if you're not planning to dim a bulb, then this point isn't critical. But if you are planning to dim a bulb, make sure you notice whether the LED can be dimmed. The label should make this clear. Many cheap LED bulbs are not dimmable.
LEDs are expected to last more than 20,000 hours, so a quality manufacturer will usually stand behind its bulbs with at least a 5-year warranty. Cheaper bulbs -- which could have a shorter life -- may not offer you that same level of confidence. They may offer very short warranties, leaving you to buy more bulbs if their lives are cut short.
With that in mind, we sell a known brand (TCP) as a 60-watt incandescent replacement at a competitive price -- approaching the price many "cheap" bulbs sell for! This TCP bulb boasts an 82 CRI and uses just 11 watts per hour, comes with a 5-year warranty, and is available with both dimmable and non-dimmable options.
Knowledge is power, and we hope this helps you to choose the right LED bulb for your needs. Of course we're always happy to provide you with lighting, and remind you that Lighting Supply has been around and well trusted since 1983, so we'll continue to be here to support you!