Incandescent Bulbs:

These bulbs have been around since the beginning.  They provide plenty of light and are cheap to purchase.  However their draw back is they convert very little electricity into light.  Its estimated that 98 % of the energy they consume is converted into Heat.

Limitations of CFL lightbulbs:

Although CFLs are an excellent source of energy-efficient lighting, they are not always the best choice for all lighting applications.

Here are a few limitations to consider:

On/Off cycling: CFLs are sensitive to frequent on/off cycling. Their rated lifetimes of 10,000 hours are reduced in applications where the light is switched on and off very often. Closets and other places where lights are needed for brief illumination should use incandescent or LED bulbs.

Dimmers: Dimmable CFLs are available for lights using a dimmer switch, but check the package; not all CFLs can be used on dimmer switches. Using a regular CFL with a dimmer can shorten the bulb life span.

Timers: Most CFLs can be used with a timer, however some timers have parts which are incompatible with CFLs; to check your timer, consult the timer package or manufacturer. Using an incompatible timer can shorten the life of a CFL bulb.

Outdoors: CFLs can be used outdoors, but should be covered or shaded from the elements. Low temperatures may reduce light levels - check the package label to see if the bulb is suited for outdoor use.
 

Retail lighting: CFLs are not spot lights. Retail store display lighting usually requires narrow focus beams for stronger spot lighting. CFLs are better for area lighting.
 

Mercury content: CFLs contain small amounts of mercury which is a toxic metal. This metal may be released if the bulb is broken, or during disposal.

LED Lighting:

LEDs (Light Emitting Diodes) are small, solid light bulbs which are extremely energy-efficient. Until recently, LEDs were limited to single-bulb use in applications such as instrument panels, electronics, pen lights and, more recently, strings of indoor and outdoor Christmas lights. 

Manufacturers have expanded the application of LEDs by "clustering" the small bulbs. The first clustered bulbs bulbs were used for battery powered items such as flashlights and headlamps. Today, LED bulbs are made using as many as 180 bulbs per cluster, and encased in diffuser lenses which spread the light in wider beams. Now available with standard bases which fit common household light fixtures, LEDs are the next generation in home lighting.

Benefits of LED lightbulbs: 
 
Long-lasting - LED bulbs last up to 10 times as long as compact fluorescents, and far longer than typical incandescents.

Durable - since LEDs do not have a filament, they are not damaged under circumstances when a regular incandescent bulb would be broken.Because they are solid, LED bulbs hold up well to jarring and bumping.

Cool - these bulbs do not cause heat build-up; LEDs produce 3.4 btu's/hour, compared to 85 for incandescent bulbs.

Mercury-free - no mercury is used in the manufacturing of LEDs.

More efficient - LED light bulbs use only 2-10 watts of electricity (1/3rd to 1/30th of Incandescent or CFL) Small LED flashlight bulbs will extend battery life 10 to 15 times longer than with incandescent bulbs. Also, because these bulbs last for years, energy is saved in maintenance and replacement costs. For example, many cities in the US are replacing their incandescent traffic lights with LED arrays because the electricity costs can be reduced by 80% or more.

Cost-effective - although LEDs are expensive, the cost is recouped over time and in battery savings. For the AC bulbs and large cluster arrays, the best value comes from commercial use where maintenance and replacement costs are expensive.

Light for remote areas - because of the low power requirement for LEDs, using solar panels becomes more practical and less expensive than running an electric line or using a generator for lighting.

Choosing an LED lightbulb: 

Many different models and styles of LED bulbs are emerging in today's marketplace. When choosing a bulb, keep in mind the following:

• Estimate desired wattage - read the package to choose desired illumination level. For example, a 3W LED is equivalent in output to a 45 W incandescent.

• Choose between warm and cool light - new LED bulbs are available in 'cool' white light, which is ideal for task lighting, and 'warm' light commonly used for accent or small area lighting.

• Standard base or pin base - LEDs are available in several types of 'pin' sockets or the standard "screw' (Edison) bases for recessed or track lighting.

The common styles of LED bulbs include the following:

Recessed/Track bulbs:

Available in pin base or standard (Edison) base, LEDs are ideal for track or recessed lighing. LEDs do not contribute to heat buildup in a room because no matter how long they remain on, they do not get hot to the touch. Also, because they are 90% more efficient than incandescants, the frequency of changing bulbs is greatly reduced.

Diffused bulbs:

In this style LED bulb, clusters of LEDs are covered by a dimpled lens which spreads the light out over a wider area. Available in a range of wattage and sizes, these bulbs have many uses, such as area lighting for small rooms, porches, reading lamps, accent lamps, hallways and low-light applications where lights remain on for extended periods.

Spotlight and Floodlight LEDs:

The spotlight LED lacks a dispersing lens, so it appears brighter as its light is directed forward. The floodlight model gives a spread-out dispersed light. Well suited for ceiling lights, outdoor floodlights, retail display lighting, landscape lighting and motion sensors.

LED Colors:

• Red - red is the traditional color for maintaining night vision.
• Green - green is now the preferred color for pilots and the military. The green color is also great for retaining night vision, and it doesn’t erase the red markings on maps and charts.
• Blue - many people like the blue because it is very easy on the eyes. Blue appears to be a good reading light for elderly eyes. Elderly folks report that they can read under the blue light for hours without eyestrain, compared to severe eyestrain in less than 30 minutes with incandescent lighting.
• White - the most popular of the LED colors. It produces a soft white light, without harsh reflection, glare or shadows.
• Amber - LED amber bulbs do not attract flying insects, as do ordinary white bulbs. Amber LEDs are used outdoors in areas such as patios and decks where insects flying around lights are a nuisance.