two of my favorite brands of markers:
Copic - quite pricey but worth the money - I get mine on sale at Hobby Lobby and when they have a coupon for 40% any one item, you can bet I will have a Copic marker in one hand and a coupon in the other
Staedtler - wonderfully fine .3mm tip in a rainbow of colors and in a nifty case that folds to stand up - again Hobby Lobby or Office Depot
The only thing I don't like about the Copic markers is that they bleed through and since my journals and sketchbooks have a big variety of paper, this happens quite a bit.
Like on this page, on the bottom left the blue marker bled through but I use it as an opporunity to paste a drawing I made that was on a scrap paper when I didn't have my book with me.
Actually I have quite a bit of "floating" random doodles. I will spend an afternoon when no inspiration is to be found and glue them on the pages of the current journal.