Travel insurance is a must when you are leaving the country. A lot of countries require you have it to get in and so do a lot of tour companies. Plus it is just plain smart.
There are a number of different coverages you will need and sometimes your current plan will already provide it, but nonetheless, you need to look into it before you leave.
Personally, one of the cheapest and effective I have found is Travel Cuts. Originally a student travel service, they do provide coverage and services to anyone now. For my age bracket (25 to 34), I can get full coverage for a month overseas for $89. This is a lot cheaper than the other providers I have found.
Repatriation means returning to your country. If something bad happens and you need to be flown home due to injury or other circumstances, that is what this money is for. Most countries require it now if you are going there. So do a lot of tour operators.
Exactly what it means. You lose you baggage and need to replace it when you get home or buy items on your trip that are necessary. If you are planning on checking luggage at all, you should get this.
Medical costs can be huge if you are in an accident, get sick, or suffer an injury from your own devices. You will want medical coverage with a decent limit (at least a million?) and a toll free number you can access from anywhere in the world.
This is coverage for cancelling your trip. Before you leave and during your trip. You can guage this amount by how much the non-refundable part of your trip is costing (flights, tours, and other deposits or services yet to be rendered).
Check over all these areas and make sure you are covered appropriately. If you know of good providers that are cheaper than Travel Cuts, let me know.