I'd dabbled in adventure games on the Spectrum, text-input stuff with the occasional splash of graphics, but I was never a devoted fan of the genre. That all changed when I got an Atari ST and was simultaneously exposed to Sierra and (then) Lucasfilm Games. The Sierra games captivated me for a while (particularly King's Quest III), but once I'd tasted the SCUMM system there was no going back. I was instantly smitten.
One particular thing about Zak McKracken was that it was funny. Really genuinely funny in all kinds of ways, from dumb slapstick to clever puns and sight gags. Even when I was completely stumped - and I often was - I just loved being in this world, and the great SCUMM system played a large part in that. Big, colorful graphics, smooth animation, and epic locations that spanned not only the Earth but visited space and Mars to boot. I remember being incredibly geekily impressed that you had to use the airlock properly on the Mars spacecraft!
The storyline was incredibly silly and that did impact negatively on the puzzles somewhat (some rather outlandish thinking was required in a few cases). Still, it wasn't enough to deter me from spending a large amount of time with the game, and I still give it a play through every couple of years. It's aged beautifully.
Zak McKracken began a long-lasting love affair with Lucasarts adventures. It was a terrifically fresh and entertaining start for me, but there was even better to come...