The best replacement for nmap is nessus.

The best alternatives to nmap are rated as following:
★★★★★  nessus
★★★★  zenmap
★★★★  wireshark
★★★★  netcat
★★★★  netstat
★★  zmap
★★  openvas
★  angry ip scanner
★  superscan
★  hping
★  unicornscan
  fping
  firewalk
  xprobe2
  nmap

Your alternative for nmap is not listed? Suggest!
Speaking about nmap, one probably shouldn't forget about os detection.

Other search terms related to nmap and their ratings are:
★★★★★ os detection
★★★★ mac address
★★★★ metasploit
★★★★ hostname
★★★ proxychains
★★ nessus
★★ zenmap
★ conficker detection
You have in mind a companion for nmap and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of nmap in all years. Click on graph for more.
nmap
nessus
zenmap