DH & I gave up drinking alcohol in restaurants/bars as a budgeting mechanism back when we were saving up for a house downpayment, and never really went back (after 8 years of abstaining, the sticker shock was ugly, so the habit just stuck. DH will occasionally have one beer, but that's it; we don't buy cocktails or bottles of wine.)
When at home or at a private party where drinks are offered, my limit is normally one, as I'm out of the habit, and the alcohol now hits me like a train.