Based on the time until treatment failure, we retrospectively analyzed 389 children to compare the long-term effectiveness of first-line antiepileptic drugs (AEDs) in children with generalized onset or unclassified epileptic seizures. Analyses were based on time until treatment failure and time until remission. In terms of time until treatment failure, the failure rates of topiramate and carbamazepine were higher than that of sodium valproate (p < 0.05). For time until 1-year remission, sodium valproate was found to be significantly better than either topiramate or carbamazepine (p < 0.05). For the subgroup with generalized onset epilepsy, sodium valproate was much better than either topiramate or carbamazepine (p < 0.05). No significant differences were found between topiramate and carbamazepine (p = 0.319). For unclassified epileptic seizures, no significant differences were found among the three AEDs. Sodium valproate should be the drug of choice for patients with children with generalized onset, and no significant differences were found among the three AEDs in unclassified epileptic seizures.