Question: Hi, I have CS5 Production Bundle (PPro + AE, etc).  I am looking for a 'Glow' plugin that is SIMILAR to the Sapphire Effect: "GLOW"  That ideally I can purchase separately or in a SMALL bundle? I can't justify $1600 even if the other effects are amazing…as I just never used them.  ANY products you can suggest?

Answer: There are a ton of glows out there. I'm attaching a small excerpt from my book Plug-in to After Effects, which gives an example of some of the glows. I'm adding extra info to the details.

1. Original Image
    
2. After Effects Glow (Free with AE). It works either on the Color Channels, which can be used for creating a glow for full-frame footage, or Alpha Channels, for creating light ray effects around layers with alphas such as text and logos. There are a decent amount of options but the look just isn’t as nice as with the third party glow options. It has no presets.
    
3. Noise Industries FxFactory (MSRP $399, TF Price: $379) The FxFactory Glow (Box-shaped) is a nice looking glow, but there are no presets. Even at a Strength value of just 0.01, the effect is still viewable. This is a great plug-in for bright bloom transitions. There is an option to Use Image Colors or to choose a Color with the eyedropper, an option not included in a lot of glow plug-ins. There is a built in Mask Tool, which has custom Mask Shapes or the option to choose a path on the layer. FxFactory is Mac only  and works in AE, FCP, Motion and Final Cut Express.
    
4. Boris Continuum Complete (MSRP $999, TF Price: $945) BCC Glow is a robust plug-in comes with multiple presets and allows for the glow to be based on RGB Channels, Luminance, Lightness, Red, Green, Blue or Alpha. There are the usual glow adjustments such as the radius, threshold and compositing mode. BCC Glow has the added options of a built in Motion Tracker, a Pixel Chooser to isolate areas of the shot and Beat Reactor, to animate with audio input.  There are quite a few glow plug-ins included and it's one of my favorites because of the variety of options and speed. We sell Continuum Complete for $945 (list price is $999) and it's well worth the price because there are so many great filters with it.

   Update: Peter McAuley of Boris FX contacted me to let me know that the filter used in the sample is now obsolete with the release of BCC 8 (looks like I need a major revision to the book!).  It was replaced with BCC Film Glow, which is "capable of generating an exact match to the Sapphire Glow filter, and in fact it even matches Sapphire Glow at it's default settings. One of the added advantages of the BCC Film Glow is that, again by default, it renders a glow all the way to the edge of the source clip… the Sapphire Glow filter stops short of the source edge, regardless of the setting used." 
    

5. GenArts Sapphire ($1699) Sapphire's S_Glow is interesting because it works with a Background and Matte layer, so it is made specifically for compositing. Width X and Width Y allow the glow to be stretched and this is not something seen in other glow plug-ins. Not only that, individual Red Green and Blue widths can be adjusted. It also has options to Glow From Alpha and Glow Under Source, so the glow can come from behind the text or keyed footage, not just on top of the image. There are no presets with S_Glow, but it’s a solid choice.
    
6. Digieffects Delirium (MSRP $299, TF Price: $284.05) Delirium's DE Glower, which does not have a lot of options but it does include the basics and the option to set a Dark Color and Bright Color, or use the Original Colors. There are a few presets as well. Delirium is fairly inexpensive and has a lot of fun filters with it. Note, the image above, from the book, is out of date. Glower is from the older version of Delirium. Delirium DE Glow is included in the new version and looks like this:

Here's another quick sample (Thanks, Brandon!)

7. Tiffen Dfx Digital Filter Suite (MSRP $599.95, TF Price: $569.95). DFX Glow is a plug-in that doesn’t seem too special on the surface but once the Color Correct settings are pulled down, there are options not seen in other glow filters. There are Hue, Saturation, Brightness, Contrast, Gamma and Red, Green and Blue controls for the color of the glow for precise control of the color. I love this package. It's mostly not glows but gels and lens effects that recreate the look of their gels and lenses in the real world.

Another option, not pictured is Red Giant Warp (MSRP $199.00, TF Price $179.10). It includes a glow plug-in.

All the plugins here are available as free trials or demos here. I'd highly recommend downloading a few and checking them out to see which gives you the look that you want. I'd definitely suggest trying the Boris Continuum Complete package and if you're on Mac, Noise Industries FxFactory.