The following list comes from job board Dice.com, who sees demand out there for the following. If you want to see this visually with graphics, see Baseline's slide show.

1. Security (with five or more years of experience and CISSP).
2. Virtualization (think VMware certification).
3. Java/J2EE (Sun certified doesn't hurt).
4. SAP (it just won't go away).
5. .NET (MCPD and Visual Studio experience)
6. DBAs (of all types)
7. Oracle
8. Project Managers
9. Sharepoint

The reason these jobs show up regularly is that they show long-term viability in technology environments. While an area like virtualization and Sharepoint are relatively newer skill sets, they make the list after a few years of solid growth in adoption and effectiveness.

It's always interesting to note how much the large vendors of IT--Microsoft, Oracle, SAP, VMware, etc.-- tend to dominate the certification and lists of these job boards. These certifications are being touted as fairly important pieces of entry lately, namely because the economy is allowing technology companies to pick from a larger pool of people, and the certifications along with work experience help establish easier levels of comparison and knowledge.