If you don't have catapults yet, you can use naval units to bombard the defenses, if the city's on the coast.
After bombarding the defenses, look at the odds. You may not need to suicide catapults if you have the right attackers (macemen, well promoted swordsmen, knights), but you're in trouble if they're on a hill or have a lot of city defender promotions.
A city raider promotion usually makes sense over a "cover" (anti-archer) promotion, since CR works against anything. Of course, many units can't get CR promotions.
If you think archers are bad, wait'll you see the longbows.