This route gives you some choices, depending on your particular interests. Peninsular Malaysia's Taman Negara preserve is hopping distance from KL, so if you want to mix history and nature, it's very easy to combine an overnight trip to Melaka with a 3-night package to the park -- I have included this itinerary below. If you want to delve deeper into rainforest habitats, fly to Kota Kinabalu and sign up for a tour of the area's national parks; specialty trips take you into wildlife preserves or trekking up Mt. Kinabalu. If it's indigenous cultures you'd like to visit, fly out to Sarawak, spend a day exploring Kuching, then join a boat trip into the interior to visit longhouse communities. The diverse range of forests in Sabah and Sarawak offers many kinds of adventures, from nature walks to animal sanctuaries, to cave exploring or white-water rafting.
Remember, if you go the outdoor adventure route, be sure to check monsoon seasons with your adventure tour coordinator. You don't want the rains to wash out your trek, or the dry season to take the rapids out of your river. Also, for dive tours, you'll have to allow extra time between flights and dives, for your body to acclimate to the change in altitudes.
Days 1 & 2: Arrive in Kuala Lumpur
After arriving in Malaysia's capital city, allow yourself a full day to recover and just spend your time wandering through the city's streets. Start at Merdeka Square, the focal point of colonial KL. Just behind the Moorish Sultan Abdul Samad Building, in the streets surrounding the Jame Mosque, you'll find KL's Little India of sorts. Continue your walk to the Central Market, where nearby coffee shops can provide a place to rest. After exploring stall after stall of Malaysian handicrafts at the Central Market, if you still have time and energy, cross the street to Chinatown, where you'll find more shopping, a street bazaar, and the Sri Mahamariaman Hindu Temple.
Day 3: Melaka (Malacca)
Take an early-morning bus to Melaka and spend the day exploring the town's historic heart. The most important things to see here are the Stadthuys, the history museum, located in the hard-to-miss red colonial building; the Cultural Museum, in a replica of a Malay-style palace; and the Baba Nyonya Heritage Museum, located inside an old millionaire's mansion. From the Baba Nyonya Museum, head to Jonker Walk to wander through temples and antiques shops.
Days 4-6: Taman Negara National Park
Take an early-morning bus back from Melaka to KL, then board an afternoon bus to Malaysia's premier and most accessible national park. Hop a boat upstream to the resort and check in for a good night's rest. Taman Negara can be done very nicely in a full-board package. You'll have the chance to jungle-trek, traverse a canopy walk, view wildlife from observation stations, go on a night trek, river-raft and fish, and meet orang asli communities.
Days 7 & 8: Back to KL
Hop a flight back to KL to prepare for your return home. If you have time, you can stock up on gifts at Kompleks Kraf Kuala Lumpur -- you'll find something for everyone on your list, in all price ranges, at this handicrafts showroom.