Sites that require long registration processes before you can do anything. Often they are just collecting the info so you are on their emailing list for marketing purposes. All these organisations think they are at the centre of the customers universe.
Sites that are slow and clunky for those of us without super fast broadband.
The train line for instance - one click! I don't think so. Quicker to walk to the station and back.
And related to registrations - blooming passwords! I have just resorted to starting a spreadsheet so that i can keep of record of passwords, logins, online identities, alternate emails etc. In case you ask it is in cryptic code that only I can understand.
And I was not that keen to receive "xx would like to be your friend" message on Facebook 6 months after they had died!
But in 2 days time we are supposed to be getting BT infinity... It will have taken them 2 whole months to get their sorry backsides around to it. During which time I have had several sets of marketing info inviting me to sign up... My nomination for an inefficient organisation award.