Rear main seal, axle seals, motor/tranny mounts, fluid, etc. Not a bad idea to change the shifter cable bushings to solid metal ones as well as the shifter base bushings.
As Dave said, start with what is worn or broken and needs to be replaced.
1999 Eclipse GS Built motor Hahn 16G Turbo w/ FMIC Hahn Stage 5 Portfueler (270's & 500's) Zeitronix Zt-2 wideband w/ 3.5bar MAP 3" SS Turbo Back CM Stage 4 Clutch and Fidanza Flywheel Baer Big Brake Kit