The distance between Singapore and Seremban is about 290 kms by road. Seremban is the capital city of Negeri Sembilan which is considered to be a dynamic fusion of a city with a homely country side. Most of the people reside in Seremban and travel to the city of Kuala Lumpur for work. Life in this city is completely stress free and also serves as one of the best vacationing get aways. Most of the people residing here are from the Chinese community. I would personally recommend you to visit Jelita Ostrich Farm.
A Bus from Singapore to Seremban is the fastest and the most comfortable mode of transport. The locals as well as the tourists prefer to cover the journey between these 2 cities by Bus precisely because there are no flights between the 2 cities and there is no direct train plying on this route. Some of the most major operators plying on this route are Eltadina, Golden Coach, Seasons Express, Grassland and The One Travel and Tours. I booked my seats from https://www.redbus.sg/bus-tickets/singapore-to-seremban through The One Travel and Tours. This Operator has about 18 departures on a daily basis and the buses start plying as early as 8:00 am in the morning till 12:00 am midnight. Personally I have always preferred to travel during the night to avoid traffic so that I can cover the journey while I am comfortably asleep in these luxurious buses. There are also some operators that operate on this prime route with VIP coaches. The air conditioned VIP coach seats only 3 in a row with one seat on the left and two on the right. This spacious layout ensures that there is enough space for people seated at the back of the bus to walk comfortably towards the entrance of the bus. The bus journey cost me about SGD30 but that is because I chose to travel during the night. If you are one of those who prefer travelling during the day the ticket would cost you somewhere about SGD18 to SGD25.
One thing that I figured out while booking my seats from redbus was that the seats are quite cheaper during weekdays and little high during week ends. The total duration of the journey is about 5 hours but this is subject to change if you are planning during the day. The bus stops in the middle of the journey for passengers who want to take a washroom break. There are several boarding points in Singapore for buses that ply to Seremban. You can conveniently select your boarding point online as per your convenience. I boarded my bus from Boon Lay shopping centre (The One Travel and Tours) with a selfish interest of window shopping till my bus arrives. Some of the other boarding points from where operators ply are the Golden Mile Complex which is one of the most traditional Bus hubs, the Textile Centre at Jalan Sultan (Eltabina Express), Holiday Inn Hotel at Outram Road (Golden Coach Express) and City Plaza at Paya Lebar MRT (Golden Coach Express).