Why would you want to...?
Alcohol and water mixtures freeze much colder than pure water (0 C) -- pure ethanol freezes at -114 C, and mixtures at temperatures between the two. Freezers are generally around -18 C, which is the freezing point of 35% ethanol.
Strong spirit drinks will remain liquid in the freezer, like the bottle of aniseed gin stuff my sister brought me from Greece -- apparently the Greeks drink it like that, presumably because it anaesthetises the taste buds.
Less-alcoholic things go to a sort of slush, with a strong alcoholic syrup running between it. I imagine the sugar in liqueurs would lower the temperature still further, and you'll get an even stickier syrup.
You do have to be careful with glass bottles. Pure spirit should be OK, but a bottle of wine or beer has enough water in it that it'll probably burst. Put it in a pop bottle first, and it should be fine (and safer if it does go). Better still a tupperware container. Liqueurs are generally not nearly as alcoholic as proper spirit, so be careful.
Also remember that the alcoholic liquid between the slush in frozen wine or beer contains everything apart from the water, including the compounds which give you a hangover (unlike proper, distilled spirit which is purified ethanol). By the way, I believe that making ice-spirit is illegal in the UK.
Once warmed up and stirred, I doubt if liqueurs would taste any worse than before they were frozen.