I was ranked 1st of all teams in Botswana after the first league round, that was one of the best achievements for me in Hattrick. Of course there's a lot of luck involved there, but hey, they're never going to be able to take that away!
A favourite part of Hattrick is when you have an Eureka-moment, when you realize you understand some part of the game better than others. Or when you win something important, like a Cup, or gain promotion to the first division. My current goal is to reach the top-10 in Belgium again and to win a Cup with more of my own youth players.
I like that Hattrick is a slow game. Here, I have time to think everything over. I also appreciate that Hattrick gives everybody the chance to be the best because you can't buy in-game advantages.
My biggest achievement in Hattrick so far is that I have won some titles with my second team in Bahrain and reached the semifinals of the National Cup in Italy, but I hope, a few months from now, that it will be winning the World Cup for the Italian NT.
What I like about the Hattrick community is that there are real people and you don't just compete against the computers. You play against each other, but you can also help each other in the forum and talk about everything.
I would say the community is the strongest reason I have stayed in Hattrick for so long. The game too of course. After having trained my players and played in the French Division 2 for a while, I started focusing on training international players to help the Moroccan team. Today 80% of the defense of the Atlas Lions was trained by me!