His information was valuable to the police.
The course was a valuable experience for me.
invaluable: very useful
Such data will prove invaluable to/for researchers.
Your advice has been invaluable to us.
The new job will provide you with invaluable experience.
indispensable: Something or someone that is indispensable is so good or important that you could not manage without it, him, or her
This book is an indispensable resource for researchers.
His long experience at the United Nations makes him indispensable to the talks.
Cars have become an indispensable part of our lives.
He became an indispensable part of the team.
be great for something (informal): to be very useful for doing something
The bag is great for taking on holiday.
Email is great for keeping in touch.