Everything (like crisps and chocolate bars) wrapped in plasticised foil that isn't biodegradable or recyclable.
Bicycle brake pad refills that cost ten quid a pair. It's a small block of rubber FFS.
eBay listings that say "from China" or "from USA" when you're on the UK site and haven't selected the international option. Have they never heard of punitive shipping, duty and VAT costs?
Starbucks coffee, which tastes like strong Happy Shopper instant with some burnt toast grated into it.
Trains without enough luggage space. Even for normal luggage, not bikes. This isn't the 1980s any more, when you could safely assume a cross-country train would only be half full.
Most Microsoft software. Excel jumped the shark after 5.0, Word after 2.0 and Windows after XP. Now it's just eye candy that gets in the way.