We live in the Milky Way galaxy, considered to be a pretty beefy example of its kind. It's a spiral galaxy, with over 200 billion stars, stretching about 150,000 (and perhaps up to 200,000) light years across its diameter.
But there are bigger galaxies out there. Malin 1, for example, looks a lot like the Milky Way, but it's 500,000 light years across (at least). UGC 1382 is another, likely also a half million light years wide. But Malin 1 is well over a billion light years away, and UGC 1382, though much closer at about 270 million light years, is actually a lightweight with far fewer stars in it than the Milky Way, despite its enormous size.