In TNG we often see a weird pecking order. For example, when Data is in command of the Enterprise in Gambit, Worf rather than Geordi serves as his First Officer, presumably because Worf was more easily replaceable in his normal position than Geordi.
Normally I'd rate it: -
Picard
Riker
Data
Geordi
Worf
in the direct command line - but we also have the bridge qualified Crusher and from season seven, Troi to consider.