There are many many threads on this topic and a quick search will get you more opinions than you could possibly want on the topic.
It all comes down to personal taste.
Multi effect pedals are convenient and generally have more effects per dollar. If you like tweaking and setting up patches etc they are fun. They are also a great way to get familiar with effects and decide what you like.
Single effects are often higher quality, simpler to use, but more expensive. You can get just the ones you want and have more choices for each rather than a package deal.
Either way, most people change their pedal boards from time to time. Buying used gear will save you $.
Enjoy
