Indeed, the tubes are only part of the tone, the whole circuitry matters.
That being said, I prefer the Fendery 6L6 amps. I love small tweed Fender Champ style amps (about 5W) like nothing else.

Traditionally, the EL84 sound is more "Marshally" - less chime, compact mids. I also own a Peavey Classic 30 which is a nice enough giggable amp, and I do like it with Les Paul type guitars, but I'm always going to my 5F1 6L6 5W amp for a tonal high. I'm addicted to the chime .

Of course, there are ways to tricking them all with a subtle pedal in front, such as a well-designed booster with a tone control and judicious use of your guitar's tone knob.

So yes, I've ranted too much, but in a couple of words, what I love is: 5F1 6L6s.