I currently have 5. My primary is at a CU, which I do my normal person banking - checking account that I pay bills with, have a vehicle loan through. Opened a savings acct. at another CU with several branches in the surrounding area for dumping purposes. Acct at Chase because they gave me $150 to open it, I get charged $10 per month service fee, but its not too big a deal to me since I pick up mass quantities of coin from them and they are always the friendliest by far. Lastly, its not really an account, but I have my mortgage through another bank that I dont have any accounts with, that I use for pickups and dump small amounts on. I just opened a new acct at a newer CU in the area in the name of my youngest child to avoid fees and use their coin counter.
I probably have too many, the only one that charges me fees currently is Chase, but to me it is worth it for what I get in return as the tellers keep an eye out for "weird" stuff and clean the magnets from the coin machines for me.