In general, most modern yo-yos that are produced by reputable companies are very smooth and vibe-free. That is, the two halves of the yo-yo are close to perfectly balanced. However, even the best yo-yos brands can produce yo-yos with some vibe. Additionally, a yo-yo can be vibe free at first but then develop vibe over time.
Sometimes this is due to roughing up the yo-yo. If you ding it off of a hard surface at the wrong angle you may cause some vibe due to damage. Sometimes however, vibe is due to something as simple as flipping over the bearing or the axle, or replacing the bearing.
If you have ever wondered if there is a way to fix vibe then you should check out the new tutorial from GSquared Jake about tuning a yo-yo. You can find the video below and it is well worth watching, especially if you are new to yo-yos and throwing. Enjoy!