I'll second the search recommendation. There's a ton of discussion on this topic.
But, in general, a few people hack up the seats themselves, generally adding gel inserts.
Others add things on top, most commonly:
Airhawk cushions
Sheepskins covers
wooden bead covers
Many of us have had custom saddles made. Among the options you'll find discussed in other threads:
- Russell Day-Long (which many consider the gold standard)
- Bill Mayer (Bill invented the Russell saddle, which relies on a lot of springs, sold the design to Russell, then started making foam based seats. "Bill Mayer" saddles are now made by his son Rocky. Had one on my Connie and loved it, but don't know if it was built by Bill or Rocky since I bought it used).
- Rick Mayer (Bill's other son. I had a Rick Mayer made for my FJR. It gets 4 out of 4 stars from me. I won't be swapping to something else. Cheaper than the Russell, a little cheaper than brother Rocky.)
- Corbin (they sell a lot of these, which means there are also a lot being resold. Check eBay if you want to go this route.)
- Sargent
Then again, many find the stock seat is just dandy. I had a tough time going over 450 miles/day on it, hence the Rick Mayer order. Before you make a change here, though, do a lot of riding and listen to your butt.