I lost my copy of Platinum (catastrophic, I know), but the team I left off with was:
Bidoof, level 5
Bidoof, level 5
Bidoof, level 5
Bidoof, level 5
Bidoof, level 5
Bidoof, level 5
...Just kidding. My real team was:
Luxio, level 22
Golbat, level 22
Prinplup, level 24
Cranidos, level 23 (traded)