Well moshi monsters was one I played (I have made like 9 accounts there because I was an 8 year old with shit memory when it comes to passwords) I remember trying to get into neopets when I was around that age but I got bored with it very quickly. But A game I played alot of was digimon world championship on the Nintendo DS. That game was amazing part raising sim(feeding, cleaning, putting them in the proper training areas for the skills you want) part battle management with a team of 3 (you can go 1 or 2 but it will be an easy loss if your digimon is not SUPER strong)