One thing I find rather interesting is my paternal granparents' accents.

My paternal grandmother came to the US from Bermuda as an adult. My paternal grandfather came to the US from Canada (New Brunswick) as an adult. They lived in Massachussettes (Framingham) for two or three decades and then settled in rural Virginia (Troy).

My grandfather and grandmother's native accents had some interesting similarities with the accents that many rural Virginians have. They all pronounce "house", "mouse", "about" and words like that almost exactly the same.