Reflector lights, which used various styles of plastic reflectors to surround the bulb, were popular during the 1950s to 1980s.
The "petals" of the reflectors acted like tiny lenses giving a jeweled effect which made the bulbs appear brighter.
Also, most sets used 6 Volt or even 12 Volt bulbs, which were brighter than the 2.5 volt bulbs used today.
Finding good sets such as these is a challenge because many were considered cheap throwaways which didn't last long.

Reflector sets were discontinued in the late 1980s because they could no longer meet the stricter safety standard imposed by Underwriters labs.
They were originally certified to the NOEL standard, (National Ornament & Electric Lights Christmas Association) a foreign safety standard which is no longer recognized in the U.S.A.
A big problem with these lights was the reflectors were very fragile - don't let the set lay on the floor while putting the lights up
or else - CRUNCH !!! - #*&# IT I stepped on another bulb!
In 2007 the reflector sets were re introduced at Christmas depot, but are now sold out.
Maybe next year these sets will be back. It just shows that everything old is new again.

A Typical package of miniature bulbs with reflectors from the 1970's (Click photo to enlarge)	These 3 styles show the reflectors evolution. A - Early hard-wired reflector, 1950s to 60s. B -  NOEL wedge base/reflector, 1970s to 80s. C -  U.L. collar style reflector, 1980s to present.
Most reflector sets were made to conform to the NOEL standard, a European safety standard. Note the fractured English of typical for imported products.	Oops - someone stepped on these bulbs! The reflectors were designed to break without exposing live wires.

Here's a sampling of reflector sets from my collection

Click on the mini image to see the full size version, then use your browsers back button to return.
Click on the light switch and you will see the set lit up.

A 100 light 5 way flasher set "Liberty Bell" brand from the late 1980's. It was sold at Channel Home Centers a now-defunct home improvement chain headquartered in the northeast U.S.A. Click the switch !
Here is a 35 light classic lights set from about 1980. It's a standard miniature set with plastic bulb covers which imitated the old C-6 Christmas bulbs. The bulb covers gave the lights a nice soft glow, rather than the pinpoints of light typical of miniature bulbs. The new LED lights use diffusers similar to these, in an example of how the classics keep reinventing themselves. Click the switch !
50 light 5 way flashing set with pointy starburst reflectors and two tone bulbs. This particular style of reflector was notorious for snagging on the wires, making it almost impossible to untangle the string ! Click the switch !
A 50 light 5 way flasher set made in Taiwan, circa 1977. This set used 12 volt bulbs the brightest of all the mini bulbs. You need sunglasses when you plug this set in! This is one of 2 found over the summer of 2002 at a flea market in Pennsylvania's Delaware Water Gap. It is mint in box and has never been used. See this set twinkling away. Click here for broadband (Large.) Click here for dial-up (Small)
A 40 light/2 way flasher reflector set from the late 1980's It had a more common petal style reflector.   Click the switch !
A 35 light reflector set from Sears, made in Taiwan, catalog no 71-94504 . This set had 2 green-tipped fuse bulbs which were similar to regular bulbs but lacked the shunt. Their purpose was to protect the string  from a current surge if too many bulbs burned out. The fuse bulbs were issued patent no 4030059 .   Click the switch !
15 light "Yuletide Bulbs" set Circa 1970, for table-top trees. This style of reflector is harder to find.   Click the switch !
Here are 2 early reflector sets by Liberty Bell. They're 15 light cactus sets, Cat no 15F, Made in Japan. This light set had the bulbs spliced directly to the wires, so that the reflectors were used to hide the splices. Note that one set has clear reflectors, while the other has them tinted to match the bulbs.
Just follow these 4 simple steps to replace the non-replaceable bulbs in the cactus light set. What !? Gee is that all it takes ?
A 36 light 4 - way flashing set "Gleam" Made in Japan This set had 2 , 120 volt miniature base flasher bulbs as you can see at the left. They were in series with the mini bulbs, which were bi-color and hard-wired into the set. When plugged in, the lights would alternately flash between the big bulbs and the mini bulbs I would guess this one dates to the early 1960s.