Some decent alternatives to mIRC:
http://www.miranda-im.org/ (what I use - multi-protocol)
x-chat 2 for windows:
http://www.silverex.org/news/
(used to use this - I configured it to beep me when a new pug had started)
go free software!
fluent you might want to make a note about using "!uset autoinvite 1" for auto-joining multiple channels on connect to avoid the "target change too fast" issue...