oops.  Typo.  Sorry!  I fixed it.  Thanks!

Of my collection, my favourites are:
-F48PG17 GE Cool White Power Grooves
-F48T12 Duro-Test Vita Lite (awesome colour & CRI, great startup flicker too)
-F20T12/BL GE blacklight (not BLB) - beautiful blue colour
-F20T12 Cool Greens (Service Long Life Guaranteed)
-F54T5 6500K Daylight High Output 4' T5
-F40T12 GE Cool White Mainlighter from the 80's
-F40T12 GE 40w Shop-Lights from the 90's (full wattage, full mercury)
-F40T12 U-Bent GE Super Cool White, one of the last with the GE endcaps
-F40T12 GE Plant & Aquarium (basically a Natural White)
-F34T12 GE Watt Misers (full mercury, have awesome startup flicker)
-F96T12 Sylvania Deluxe Cool White Slimlines
-F48T12 GE Watt-Miser slimline, 30w with red etch
-Chinese-made 13w PL-S lamps of 6500K daylight colour (I have two)
-Philips 13w PL-C and PL-S 4100K two-pin CFL's
-F15T8 Sylvania Designer Cool Whites (2)
-LOA quad 18w 4-pin CFL's made by Panasonic
-LOA circline 22w Warm White (the colour grew on me)
-The many Sylvania Sunshine 5000K F40T12s and GE Residential Light 4100K F40T12's

Almost all of these lamps are in regular use...why have it if you aren't going to burn it?

Almost all of these lamps are in regular use...why have it if you aren't going to burn it?

I gotta agree!  I use as many of mine as I can also!  98% or more of what I have in regular use is preheat fluorescent.

My favorites are the Westinghouse variety, with older GE and Sylvania not too far behind. Also like the Duro-Test fluorescent lamps, especially the power twists. Of the modern lamps, at least GE and Sylvania  F40T12s are decent.

Here are what I have in use in my fluorescent lights:

Ott-Lite F40T10 2x
GE F40CW Mainlighter 2x
Westinghouse F40CW 2x
Sylvania F40CW Lifeline 1x
Sylvania F40 Cool White Plus 1x
Sylvania F40DX 4x
Philips F40 Cool White Plus 2x (alto crap but I'm using em up)
GE F15T12/CW 2x
GE F14T12/CW 2x
Sylvania FC12T9/WW 1x
GE F20T12/CW 2x
Sylvania F20T12/CW 1x
Westinghouse F20T12/CWX 1x
Sylvania F30T12/WWX/RS 2x

Plus lots more stored in my fluorescent lamp boxes.

I currently use:

- A pair of modern Sylvania F20T12/CW on an Advance ballast, which I seriously think to change, way too dim...  

- A pair of mid-90s GE F20T12/D on preheat chokes, much brighter than the Sylvanias

- A pair of Sylvania F32T8/CW, one 741 and one 841. By chance these have found an useful application in my workshop with that shoplight I got a while ago. Otherwise they would collect dust LOL.

- A GE F15T8/CW (from Indonesia) in my closet, here again another tube that would collect dust if not used.

I also have a GE F40D Mainlighter and a Sylvania F96T12/CW/SS that wait to be used.

My favorites are definitely CGEs. Otherwise I don't have "favorites", I like fluorescents in general, but as a Canadian, CGE fluorescents have a special place in my collection  

My new favorites are Sylvania Cool White Plus F40T12/CWP 4' lamps. I just bought a ten pack of them because the specs are pretty close to the "real" F40T12 cool white lamps. From what I can tell, these are regular cool white lamps with just enough "good" phosphor to bring the CRI up to 70 to meet federal regulations. I'm not sure exactly what the difference is in the phosphor, though. If I get a chance, I will light one of these up next to a regular cool white and take a picture.

I would use these any day over 34 watt lamps and I bought these for the same price as a 34 watt lamp.

-Nelson

Those are still full mercury too.

@nogden:
 I guess it would be mix of halophosphates and rare earth "tri-phosphor". The reason would not be the CRI, but the efficacy - Triphosphors are ~20% more efficient in lumens (in radiated energy even more, as triphosphors radiate relatively more in the red and blue, where the eye is not as sensitive)

A few favorites:
Philips F40T12/50U (5000k Ultralume) -- clean white color & bright
GE F40G (F40T12 Green) -- Green phosphor (looks white when off), these have awesome color & brightness.
GE F40CG (F40T12 Cool Green) -- nice color
GE F40C75 (F40T12 Chroma 75) -- 7500k color temp, slightly more 'blue' than than a "daylight" lamp
Philips TL 40W/03 RS (F40T12 Actinic 03) -- blue/uv saltwater aquarium bulb

A few faves from collection.

Philips TL20W/17 (green 2' bought in Brussels in July 1981, made June 1979)

Metrovick 3' T8 warm white 29 (Made in UK, 1960s - date code "75") given to me by a cafe owner in Charing Cross Rd London, early 90s in exchange for a Thorn of same size and colour after I spotted the lamp in use in a window display!

Philips TL8W/35 (Made Oct 1974, first of these found in the autumn of 1977) that has been "perfectly worn" with thick off-cathode bands on each end, neatly-formed anode spots, etc but still lights perfectly on magnetic choke and Multipulse electronic starter.

Airam L20W/3XX "Lammin de Luxe" (appears to match Philips colour 32, made in Finland Jan 1978).

Irisfluor (UK-imported French Mazda/French Philips) TF20W/29, well-used but healthy, made Jan 1976, found in 1978 or 1979 at Royal Free Hosp London after they'd been relamping. No 2D's, CFL's or LED's then!

Canadian GE F17T8/835. Works perfectly on standard UK 20w control gear, bought @ Canadian Tire while on hol in Toronto, June 2008. No cathode shields. I'm more of a nostalgic Halophosphate man myself, but rather like 835. Certainly DON'T like the scourge of 860 cold blue daylight lamps creeping their way into every shop on the high street these days. Those tubes make the whole shop look cold and less inviting than in the days of the good old Warm White 29 that was once everywere - rant over!

Circular Dutch Philips 32W DELUXE WW 32, made April 1964, found in Brighton in July 1986, and managed to survive the train journey back in one piece. Almost everything the cathodes could give is on the tube wall, and it works and starts reliably, but with about as much light as a T5 6W the same colour. It's the earliest Philips lamp I have with the alphanumeric M/Y coding on it.

I've never noticed this thread before.

My favourite brand is Atlas which was made by Thorn. Some of the tubes used to use special braided cathodes made of 8 thin tungsten wires braided together to form a mesh cylinder. They used to hold ridiculously high amounts of emitter and would last ages!

Thorn tubes in general are another favourite of mine, the older ones seemed to last the longest. I've seen quite a few Thorn tubes in shops still going.

Favourite colour is a difficult choice as I like almost all the colours. I prefer cooler colours but I'm not too keen on retrofitting daylight tubes into existing installations, usually there isn't enough light and it makes the room look cold.

I should think Natural (Universal White) is probably the best mix of good colour rendition and efficacy. Thorn Kolorite or Philips Trucolor look great but the tubes tend to be quite dim.

Favourites in my collection are:

Atlas Daylight 4300K 6ft 85W
Osram-GEC Natural 4000K 6ft 75-85W
Endura White 3500K 2ft 40W
Philips MCFE White 5ft 65/80W with brass caps

Modern for me is anything by philips, I believe they make the best modern T8 lamps. As for vintage, My atlas Superfive Blue is my favorite!

Some of my favorites have changed, as I have learned the value of some lamps since joining this site.  I have several of the "3" General electric F40s, which are now put away, along with several inside etch "Mainlighter" GE F40s.  I have a variety of Westinghouse F40 black ender lamps that I took out of regular service to put in the "collection", especially since I have scored so many good, working full mercury lamps at the recycle center.  In my "put away" collection, I also have a variety of "Lifeline" Sylvania F40s, 20 something 6 foot "Powergroove" T17 lamps, various old under 4' lamps and even a few old slimline lamps.  My favorite "modern" lamps are the full mercury Sylvanias and I love the colored lamps (green, red, blue, gold, cool green and blacklight blue).

There's a few more i need to add to my list of favorites:
F40T12/Red (dim, but awesome color)..F96T12 Red's are cool too
Sylvania F40/IF (Incandescent Fluorescent - cool color, has a 'vintage' look to it - appears to be closer to a real incandescent than warm white...but not very bright)

And for modern lamps:
F54T5/Red/HO - (4-foot High Output T5 "Red" ... which is more pink than red, awesome color & very bright!)

Yes, xmaslightguy, I forgot about the IFs!!  They are cool!  I would love some 8 foot colored lamps, but the 4' ones will always be my favorites, besides the 5' T17s!