Oil-based fragrances wear closer to the skin, so aren't as bold as alcohol-based perfumes, but they can last longer on the skin than a spray. Choose oil-based if you like your perfume to be more subtle but longer-lasting, or if you prefer a fragrance that is deeper in tone, rather than fresh.
Eau de parfum has more "lift" and will show up the lighter, fresher top notes than an oil-based fragrance. Choose eau de parfum is you prefer a fragrance that projects and is more noticeable to those around you, or if you love the smell of lighter fresher notes.
You can also layer your fragrance for a longer-lasting scent: perfume oil first, followed by eau de parfum.