Which was your first complete set?

[Ponybookworm]

Mine was the Sundae best ponies. Simply because I had the entire set as a kid
As a collector I actually don't remember which set I completed first 

Same!!! In fact this post added a new column to my G1 spreadsheet I'm working on...

[FernMariposa919]

Hmmm. I completed a couple of sets around the same time, so I'm not sure which one was my first.

I have the complete set of the first set of rainbow ponies. I only have half of the second set.

I also have all the earth ponies, pegasuses, and unicorns from year 3. I don't know if each is counted as separate sets or they're all lumped together.

[Leave a Whisper]

I don't have the complete set anymore as I wasn't planning on keeping them all, but it would be the Retro Mane Six Pack.

[reanna-mator]

I think it was the original six when I started collecting.

[StrawberrySparkle]

To date my only complete set are the wave 1 rainbow ponies

[cowboyopossum]

i believe my first complete set was the Twilight pony wedding bridle friends pack, though i have long since lost everything but twilight herself and the necklace 

[Taffeta]

The Rockin' Beats. It's the only set I owned complete as a child, so it's an easy one to answer.

My sister and I had a few baby sets complete between us as well, like we both had baby susie, I had billie and she had katie. But the Rockin' Beats was the first and only set I had complete myself as a kid. And probably the first we had either of us as well.

[Tropical_Sunset]

Sundae Best, though I sold them.

[SkyCakes]

I think it was the orginal six. I think they were CC. im not sure its been so long I forgot.

[Carrehz]

Ooh, good question. I'm not really a set completer (it's rare I like ALL the ponies in a set; I'm not a completist, I just get the ones I like) so let's see....

Overall it's definitely G1 Dollymix, but just counting the actual Hasbro ponies, I think it'd be the Big Brothers?