Some are strong, and some are weak. The weak, as is well known, are easily mastered—completely regular and, frankly, pathetic. But it doesn't have to be that way! The Society for the Strengthening of Verbs labors at its noble cause of strengthening verbs and nouns (in English too, though with less Sprachgefühl), increasing the stock of causatives, and generally messing around with German (excuse me, with Neutsch).
WebVerbix can conjugate verbs for you sixty-four languages, ranging from French and Spanish to Dutch and a variety of creoles. The best part is that it'll do it for free (though you can buy the software and conjugate in 100 languages.) It's sites like these that remind me why I love the Internet.