My Least Favorite Feature: Autoplay Flash and/or Music
As someone that spends a LOT of time surfing sites in the course of working in the directory biz, I can say that if I could only give ONE tip to a client... it is to skip adding an autoplay flash animation that comes on when you enter the site.
There are other things that raise my hackles, but punching in a URL and immediately getting some narcissistic lawyer or somesuch in my face telling me why using their services is the only thing between myself and total destruction is every bit as annoying as that freakin auto-launch MIDI music back in the 90's ever was.
If you want to put a clickable animated feature that the user can CHOOSE to play... wonderful... but forcing an animation on the surfer is the sensory equivalent of rape. For God's sake do not insist they see your @#$! video just because you can. Personally unless I absolutely have to see the site for business reasons I immediately LEAVE the second I'm met with an autoplay.
THIS INCLUDES AUTOPLAY ADS, TOO.
It's kinda like having an animated gif of a mailbox opening and closing as an email avatar, or a background that twinkles the whole time you're on the site. Being able to doesn't make it a good idea.
Please feel free to discuss, or share your own pet peeves
This info might come in handy if you're building a site for a client and they insist on some feature you know is gonna bite them in the butt.