Keep your call history forever and list them category wise for ease of access.
Call History : Call Detail Any Number allows you to export calls to excel file. This app can backup your logs and restore them on same phone or other. There is a useful statistics page to give you more insight about calls you are making/receiving.
Call History Manager keep your call history forever and list them category wise for ease of access. Quick and advanced search options helps you to easily access data you are looking for.
Auto backup is another useful option to keep call history safe. Even if app malfunctions and you need to re-install, you will be able to restore all your history from auto backup file.