I was first introduced to MTG when Portal came out in 1997, after getting a few free cards. I saw boxes in stores but didn't really get into the game until 1999 (when Sixth Edition and Mercadian Masques were released). I got one of those two-player starter decks. I played casual games with crap like Trained Orgg, eventually getting older cards from friends that also played -- some good (Dark Ritual) and some not as good (Skittering Skirge). It was an entertaining hobby but I never went anywhere serious with what I did. I didn't even know about FNMs until later on.
The Odyssey block (2001-2002) grabbed me and I thought it was fun. The first 'real' decks I remember using were a modified B/R theme deck from Torment and an U/G homebrew with Thorn Elemental and a bunch of Apocalypse cards (I've had a soft spot for U/G ever since, including Madness and Turboland). They weren't the greatest decks but I had fun playing with friends. And that's what I've found to be the best part about Magic -- getting together with some cool people and tapping cards. I slowly stopped playing again as time went on, since I wasn't a competitive-oriented player.
When Lorwyn came out, I found that one of my college roommates played MTG. I dug out my boxes of old cards, checked out some newer stuff, and began to play again. My decks started to become decent. After my roommate moved out, I began to play less (a recurring theme) but one day I saw the two new roommates playing some MTG on an Xbox 360. It was the first Duels of the Planeswalkers, and the idea of being able to play on a console piqued my interest.
I told my roommates about paper Magic (they had no idea it existed) and convinced them to try it out. They bought a bunch of old cards off eBay for cheap, slapped together some awful decks (one tried a B/G control deck with over 100 cards in it), and soon it was almost like I was playing back in the early days again. The nostalgia was great, and I still enjoyed playing the game, but all of my decks were too powerful for beginners. I helped them get better, and the games became more fun for everyone. One guy made a mono-black Wither deck that was brutal in multiplayer, and the other made a strong Furnace of Rath burn deck.
My roommates created a MTG club at the college, which attracted a surprising number of people. Some of the players that showed up were competitive tournament-entering players, and one in particular had a lot of experience. We all had to get good quickly in order for games to be as fair and fun as possible, and most of us turned our focus from casual to Standard. Competitive can be fun in its own way with the downside of being more expensive. It requires a hefty investment of time and money, but I still like it. I've become a much better player by playing with good players and making countless decks.
Crowning achievement: A turn-3 Ulamog, the Infinite Gyre in a Zendikar tournament, via a hardcasted Summoning Trap.