Core beefsteak tomatoes; cut each into 8 wedges. Halve grape and cherry tomatoes; leave pear tomatoes whole.
Make dressing: In a small bowl, whisk together vinegar and oil; season with salt and pepper. In a large bowl, toss arugula with half the dressing. Divide arugula and tomatoes evenly among four serving plates; drizzle tomatoes with remaining dressing. Serve immediately.