the original ads (G1) did it for me.
i was just sold on the whole concept as there was nothing like it at the time (gobots excluded

)
i couldnt even BUY the damn things in ireland at the time having to go to newry in northern ireland and even then when i was asking around about them the lad in the toy store tried to send me to an electrical shop !
only really wanted skywarp and jazz but EVERYTHING was sold out except a few gobots and a soundwave.
suffice to say i made the right choice there

the TV show didnt show up for ages. at first only being shown in five minute parts (yes you read that right, ONE episode split into five minute parts spread over a mon to fri week) and then only on cable.
i just loved the originality of the concept. i remember trying to imagine what cybertron would look like before i seen it and failing miserably when finally seeing the place.
TBH whats kept me though is probably the comic. simon furman did more to cement this in my blood than anything. the first comic i got was shooting star in the UK comic by budianski but when furman kicked in with in the national insterest and then target 2006 i was in love.
transformers is pretty much the first thing i took to myself (as opposed to inheriting the interest from my brother in terms of his comic book collection) and will always have a place in my heart because of that.