Transunion.
I went from a 300 dollar credit limit - with 1 card, to 500 limit increase, after a few months. I waited about a year and got a discover card with a $1500 limit, and then 3 months later (around nowish) I applied for bestbuy credit and got a $2000 limit. I always paid what I owed off a week before the payment was due, and if i left anything unpaid it was 25 dollars, never any more.