Just to mention a few. The list goes all the way up to 50k or so!!

1/udp open tcpmux
2/udp open compressnet
3/udp open compressnet
4/udp open unknown
5/udp open rje
6/udp open unknown
7/udp open echo
8/udp open unknown
9/udp open discard
10/udp open unknown
11/udp open systat
12/udp open unknown
13/udp open daytime
14/udp open unknown
15/udp open unknown
16/udp open unknown
17/udp open qotd
18/udp open msp
19/udp open chargen
20/udp open ftp-data
21/udp open ftp
22/udp open ssh
23/udp open telnet
24/udp open priv-mail
25/udp open smtp
26/udp open unknown
27/udp open nsw-fe
28/udp open unknown
29/udp open msg-icp
30/udp open unknown
31/udp open msg-auth
32/udp open unknown
33/udp open dsp
34/udp open unknown
35/udp open priv-print
36/udp open unknown
37/udp open time
38/udp open rap
39/udp open rlp
40/udp open unknown
41/udp open graphics
42/udp open nameserver
43/udp open shois
44/udp open mpm-flags
45/udp open mpm
46/udp open mpm-snd
47/udp open ni-ftp
48/udp open auditd
49/udp open tacacs
50/udp open re-mail-ck
51/udp open la-maint
52/udp open xns-time
53/udp open domain
54/udp open xns-ch
55/udp open isi-gl
56/udp open xns-auth
57/udp open priv-term
58/udp open xns-mail
59/udp open priv-file
60/udp open unknown
61/udp open ni-mail
62/udp open acas
63/udp open via-ftp
64/udp open covia
65/udp open tacacs-ds
66/udp open sql*net
67/udp open bootps
68/udp open bootpc
69/udp open tftp
70/udp open gopher
71/udp open netrjs-1
72/udp open netrjs-2
73/udp open netrjs-3
74/udp open netrjs-4