Which do you think should be prioritized first, clients or employees?

Might be client ... But another way to tackle this situation is, Say first we shall maintain a Good and Healthy relationship with Staff Because it's the staff through which we start our business and then Clients through them we run our Business(Revenue). If our staff is In healthy and good environment, It's indirect Impact would be good quality and quantity Production, Positive work Environment, Motivation, Good impression on client, Growth in clients, etc. If client is impressed with our work and at the same time our staff is well settled, It would be unfair to say the client may go !! 

for sure clients. because if we wouldn't have clients then we wouldn't have employees and this what should all employees realize without clients will be no job.

I think that our clients should be number one even though we have any problems at our company