Speaking as a professional, your question doesn't make sense without additional info from you. It's like asking what's the best car to get.
It depends on a lot of factors, like:
1) what you need
2) what you like
3) what you can afford
4) availability of practitioners in your area
Swedish is of course just fine for basic relaxation and numerous ailments, Sports massage obviously deals with sports-related stresses and injuries, shiatsu uses the body's energy pathways to heal and invigorate.
Maybe you could use deep-tissue, if that's where your problem is, it's not as useful if your problem isn't deep.
But it's a rare person who knows deep-tissue and not basic swedish as well.
Now even with a lot of research into which type would be right for you at the moment, it's still trial and error as far as finding the right practitioner to apply that modality.
So what exactly do you hope to get out of a massage?