For the 2.3 W201:
According to the wizards at Stuttgart:
Inspection at 800-1000 miles
Lubrication Service every 7,500 miles or twice a year (spring & fall)
Maintenance Service every 15,000 miles or two years
Additional Work every 30,000 miles
MB suggested replacing oil and filter every 3750 miles for "hard and sporty" driving
Auto trans fluid change every 15,000 miles, filter and fluid at 30K intervals
Brake fluid annually, preferably in the spring.
Coolant change at least every 3 years.
Lube enging throttle, linkage rods and shafts every 7,500 or twice a year (thats a lot of grease!)
Cats might need replacement after 50K miles
Every 15K: oil/filter, new plugs, lube throttle parts, door hinges, door locks and hood. Check fluid levels, inspect everything else for wear and tear.
Every 30K: oil/filter, air filter, check V-belt, replace O2 sensor (warning light comes on @ 60K), replace plugs, check clutch, flex discs
Every 60K: Replace fuel filter
Once a year: Replace brake fluid, clean water drains, clean and lube sunroof rails and sliding blocks