Pretty sure you need to take your total (as in, buffed for the content you're doing) Penetration into account. If you're not at/near the cap, you want a sharpened dagger or a precise mace in the off-hand, I believe. Sharp Dagger vs Precise Mace is like 1% tradeoff vs the other, though, so it matters little unless you're dealing with super precise number crunching. Pick whichever one tickles your *** more, if you don't have a compelling reason to care about that 1ish percent.

But yeah, assuming you're already gonna be close enough to the pen cap in your group or whatever, stack more crit chance. Daggers is the choice then; don't wanna overpen, unless we're talking PvP here.