This a a pretty pimp little tool that will help you build effiencent password cracking dictionaries:

http://code.google.com/p/l517/

Default passwords can be obtained from the following websites:

http://www.phenoelit-us.org/dpl/dpl.html
http://cirt.net/passwords
http://www.defaultpassword.com
http://www.passwordsdatabase.com
http://www.isdpodcast.com/resources/62k-common-passwords/

http://www.insidepro.com/eng/download.shtml
http://www.insidepro.com/tables.php

Collection of Wordlist v.2 374806023
(3.9GB / 539MB) Part 1, Part 2, Part 3 5510122c3c27c97b2243208ec580cc67
http://thepiratebay.org/torrent/6300469/Collection_of_Wordlist_%28Dictionaries%29___V.2_NEW____for_Cracking_
http://www.mediafire.com/download.php?e5v4q79yf7d5r3a
http://www.mediafire.com/download.php?o8ri742gair8g6d
http://www.mediafire.com/download.php?7w695b1k1b1b903

HuegelCDC 53059218
(508MB / 64MB) Part 1 52f42b3088fcb508ddbe4427e8015be6
http://www.megaupload.com/?d=SNK18CU0
http://www.mediafire.com/?blvzrvqlrvrm0ny

Naxxatoe-Dict-Total-New 4239459985
(25GB / 1.1GB) Part 1, Part 2, Part 3
Part 4, Part 5, Part 6 e52d0651d742a7d8eafdb66283b75e12
http://diablohorn.wordpress.com/2010/03/21/gotta-love-compression/
http://www.mediafire.com/download.php?kvntczux7i5bo2c
http://www.mediafire.com/download.php?3czep4kxmso1kd7
http://www.mediafire.com/download.php?twdlv7tf9f0xbdg
http://www.mediafire.com/download.php?cct41buudrcy0ss
http://www.mediafire.com/download.php?6oakueb1vhg414x
http://www.mediafire.com/download.php?8v3f64p6pd349ix

Purehates Word list 165824917
(1.7GB / 250MB) Part 1, Part 2 c5dd37f2b3993df0b56a0d0eba5fd948
http://h33t.com/details.php?id=178f55c67ca0f522831dbc67042a34983e6652f5
http://www.mediafire.com/download.php?98u8d4qe803erm8
http://www.mediafire.com/download.php?dvi0bjbhxkn05hl

theargonlistver1 4865840
(52MB / 15MB) Part 1 b156e46eab541ee296d1be3206b0918d
http://www.mediafire.com/?fmz1q3nhnz0
http://www.mediafire.com/download.php?mwu8ivr0nqn5eeq

theargonlistver2 46428068
(297MB / 32MB) Part 1 41227b1698770ea95e96b15fd9b7fc6a
http://thepiratebay.org/torrent/3833663/The_Argon_list_ver.2_Password_dictionary_2.3gig_Jo-Psyko_
http://www.mediafire.com/download.php?ixcih9rgrczrpmj

theargonlistver2-v2 (word.lst.s.u.john.s.u.200) 244752784
(2.2GB / 219MB) Part 1, Part 2 36f47a35dd0d995c8703199a09513259
http://rapidshare.com/files/98912262/theargonlistver2_wordlist.zip.html
http://www.mediafire.com/download.php?yj31a3ic2zohai3
http://www.mediafire.com/download.php?x9ejmh9yp71dh8r

WordList Collection 472603140
(4.9GB / 1.4GB) Part 1, Part 2, Part 3, Part 4, Part 5, Part 6, Part 7 a76e7b1d80ae47909b5a0baa4c414194
http://www.torrentroom.com/torrent/3074471-WordList-Collection.html#b3
http://www.mediafire.com/download.php?mbu3mdl2mzi227h
http://www.mediafire.com/download.php?z3jjaq3pe384yvl
http://www.mediafire.com/download.php?wt7qqt57d4rp0kv
http://www.mediafire.com/download.php?8zglksb3k7b7746
http://www.mediafire.com/download.php?9yjzcprc76ats4g
http://www.mediafire.com/download.php?pxm1a3muicyrkyr
http://www.mediafire.com/download.php?98p2jdlph15a8b9

wordlist-final 8287890
(80MB / 19MB) Part 1 db2de90185af33b017b00424aaf85f77
http://torrentz.eu/87e820583d71a3bb7d43e2a3b1d4eb3d7231e606
http://www.mediafire.com/download.php?nb4j6b4p2c2f5kv

wordlists-sorted 65581967
(687MB / 168MB) Part 1 2537a72f729e660d87b4765621b8c4bc
http://diablohorn.tbhost.eu/distribute/wordlists-sorted.gz.torrent
http://www.mediafire.com/download.php?6356dax1xi6c2ct

wpalist 37520637
(422MB / 66MB) Part 1 9cb032c0efc41f2b377147bf53745fd5
http://www.megaupload.com/?d=7RN6ZB2E

WPA-PSK WORDLIST (40 MB) 2829412
(32MB / 8.7MB) Part 1 de45bf21e85b7175cabb6e41c509a787
http://thepiratebay.org/torrent/4428301/
http://www.mediafire.com/download.php?ko3k5waryr254gq

WPA-PSK WORDLIST 2 (107 MB) 5062241
(55MB / 15MB) Part 1 684c5552b307b4c9e4f6eed86208c991
http://thepiratebay.org/torrent/4433853/WPA-PSK_WORDLIST_2_%28107_MB%29.rar
http://www.mediafire.com/download.php?ccdqo2s6ar75320

WPA-PSK WORDLIST 3 Final (13 GB) 611419293
(6.8GB / 1.4GB) Part 1, Part 2, Part 3, Part 4, Part 5, Part 6, Part 7 58747c6dea104a48016a1fbc97942c14
http://thepiratebay.org/torrent/5945498/WPA-PSK_WORDLIST_3_Final_%2813_GB%29.rar
http://www.mediafire.com/download.php?beyf2gbs07wl6zn
http://www.mediafire.com/download.php?scc21q07rdaamzd
http://www.mediafire.com/download.php?urcrd1lk1bjts1e
http://www.mediafire.com/download.php?k74hl5ud35ytzzv
http://www.mediafire.com/download.php?yras8iih4739hlt
http://www.mediafire.com/download.php?e8ycntc5qnsxbnn
http://www.mediafire.com/download.php?i7apnn6rgpal937

-=Xploitz=- Vol 1 - PASSWORD DVD 100944487
(906MB / 109MB) Part 1 38eae1054a07cb894ca5587b279e39e4
http://thepiratebay.org/torrent/4017231/
http://www.mediafire.com/download.php?pjs2s64pj0uw66f

-=Xploitz=- Vol 2 - Master Password Collection 87565344
(1.1GB / 158MB) Part 1 53f0546151fc2c74c8f19a54f9c17099
http://www.backtrack-linux.org/forums/old-general-discussion/8603-=xploitz=-2-master-password-collections.html
http://www.mediafire.com/download.php?n3ofy96p5lbkvr3

-=Xploitz Pirates=- Masters Password Collection #1! -- Optimized 79523622
(937MB / 134MB) Part 1 6dd2c32321161739563d0e428f5362f4
http://thepiratebay.org/torrent/5079163
http://www.mediafire.com/download.php?rjqlmfkokn5fpzq

17-in-1 5341231112
(37GB / 4.5GB) Part 1 - Part 24 d1f8abd4cb16d2280efb34998d41f604
http://www.mediafire.com/?k3j1ngab1bg3m

18-in-1 5343814622
(37GB / 4.5GB) Part 1 - Part 24 aee6d1a230fdad3b514a02eb07a95226
http://www.mediafire.com/?t150bv7govzsr

18-in-1 [WPA Edition] 1130701596
(12.6GB / 2.9GB) Part 1 - Part 15
425d47c549232b62dbb0e71b8394e9d9
http://www.mediafire.com/?lpkepzdz3mmg0

36GB wordlist that can be very very useful for cracking accounts
compression, it's "only" 723MB
http://www.megaupload.com/?d=7ZLNVV8D

Openwall Wordlists Collection CD
Included in this collection are wordlists for 20+ human languages and lists of common passwords. The included languages are: Afrikaans, Croatian, Czech, Danish, Dutch, English, Finnish, French, German, Hungarian, Italian, Japanese, Latin, Norwegian, Polish, Russian, Spanish, Swahili, Swedish, Turkish, and Yiddish. There's also a list of the common passwords and unique words for all the languages combined in one file (over 40 MB for almost 4 million entries).
http://www.megaupload.com/?d=Y5OPKI21

It has ~1 Billion WPA optimized passwords.
http://thepiratebay.org/torrent/5945498/WPA-PSK_WORDLIST_3_Final_(13_GB).rar

Here is the list of 1,717,681 passwords:
http://dazzlepod.com/site_media/txt/passwords.txt
UNIQPASS Free 2 million randomly selected passwords (18.9MB).
http://dazzlepod.com/site_media/txt/uniqpass_preview.txt

1.5GB_Wordlist_by_MAsH
http://svn.isdpodcast.com/wordlists/1.5GB_Wordlist_by_MAsH.txt.tar.gz

1 Password dictionaries
2 Leaked passwords
2.1 Statistics
3 Miscellaneous non-hacking dictionaries
3.1 Facebook lists
http://www.skullsecurity.org/wiki/index.php/Passwords