ohtapoo.com
sounds good

WordPressプラグイン

http://matome.naver.jp/odai/2133664566942352101

SPAM）
Akismet

http://www.ad-minister.net/2008/01/25/all_in_one_seo_pack_japanized/

Google (XML) Sitemaps Generator for WordPress

http://www.arnebrachhold.de/projects/wordpress-plugins/google-xml-sitemaps-generator/

404 Notifier

http://wordpress.org/extend/plugins/404-notifier/

Redirection

http://wordpress.org/extend/plugins/redirection/

Broken Link Checker

http://wordpress.org/extend/plugins/broken-link-checker/

SPEED）
Quick Cache

http://wordpress.org/extend/plugins/quick-cache/

Head Cleaner

http://wordpress.org/extend/plugins/head-cleaner/

Revision Control

http://wordpress.org/extend/plugins/revision-control/

Delete-Revision

http://wordpress.org/extend/plugins/delete-revision/

Analytis）
Ultimate Google Analytics

http://wordpress.org/extend/plugins/ultimate-google-analytics/

Google Analytics Dashboard

http://www.ioncannon.net/projects/google-analytics-dashboard-wordpress-widget/

FeedLogger

http://techblog.ecstudio.jp/tech-tips/wordpress/feedlogger.html

Search Meter

http://wordpress.org/extend/plugins/search-meter/

Social Metrics for Japanese

http://kachibito.net/wordpress/social-metrics-for-japanese.html

Mobile）
Ktai Style (携帯対応プラグイン)

http://wppluginsj.sourceforge.jp/ktai_style/

WPtouch

http://www.bravenewcode.com/store/plugins/wptouch-pro/

Others)
Contact Form 7

http://contactform7.com/

http://www.seotemplate.biz/blog/wordpress-plug/883/

WP-PageNavi

http://wordpress.org/extend/plugins/wp-pagenavi/

ページナビゲーションを拡張してくれるプラグインです。
WP Multibyte Patch

http://eastcoder.com/code/wp-multibyte-patch/

Tools）
Simple Tags

http://wordpress.org/extend/plugins/simple-tags/

PS Auto Sitemap

http://wordpress.org/extend/plugins/ps-auto-sitemap/

WP Social Bookmarking Light

http://wordpress.org/extend/plugins/wp-social-bookmarking-light/

WP To Top

http://wordpress.org/extend/plugins/wp-to-top/

Internal Link Building

http://seoroi.com/specialty-services/new-seo-plugin-for-wordpress-internal-link-building/

My Category Order

http://wordpress.org/extend/plugins/my-category-order/

WP-DBManager

http://wordpress.org/extend/plugins/wp-dbmanager/

Hot Linked Image Cacher

http://wordpress.org/extend/plugins/hot-linked-image-cacher/

Hot Linked Image Cacher | Mituru Room

http://www.mituru.jp/2011/10/04/hot-linked-image-cacher/

WPでamazonアフィリエイト

http://blog.solid-peat.com/2010/07/31/wordpress_amazon_affiliate_plugin/

WPで楽天アフィリエイト

http://mauyas.com/archives/1419