I have one of mine in with:
6 Tetras (4 Bleeding Hearts and 2 Red Minor Tetras),
3 Bristlenose Plecos (plus one 3-month-old),
1 Rubbernose Pleco,
7 Yoyo Loaches,
1 Clown Loach,
2 Kuhli Loaches
I've discovered that if you put a young Betta (very small, was being sold as a female but is a very good looking male plakat) in a big tank after he's lived a significant amount of time in a little cup, he'll be stressed and confused. I've had him for less than a week and he's still adjusting to this new world, though he no longer acts crazy, flying around and showing a subtle hint of stress stripes. It's kinda cute, though, watching him during feeding time. Like the other day, he noticed food was floating down, so he checked it out, then noticed the Rubbernose through some gaps in the driftwood (he actually tilted this way and that to try to see the Pleco better). Then he noticed 2 or 3 Yoyos battling over a wafer and bent down to watch them. Then he meandered off to get some air and noticed some food floating there. Then I left, lol