Don't use Comic Sans. I don't personally think it's a bad font, but it only looks good if it fits your game. What's more, millions of people utterly hate the font and will refuse to play anything written in it. So even if you personally like that font, don't use it, unless you want people to not like your game. It's like cutting yourself in the fingers.
What you can use is a good readable font. Arial may be a bit too plain, but there are other fonts out there. Myriad Pro is one of my personal favorites. Try to avoid serif fonts unless necessary. You can ofcourse use an original font in your game with a special theme, but remember the most important thing about a font is that it's clearly readable, not that it looks fancy.