i'm going for a couple of lavender plants either side of the front door this year. they like dry sunny conditions so should do well being ignored. whilst not exactly evergreen, they are perennials and their foliage does last.
Last year I planted a Periwinkle (Vinca) in a tall old chimney pot at my front door. It's done really brilliantly and was beautiful when it flowered. The flowers are a gorgeous pale blue/purple and it flowered for ages. It trails all over the sides and I've just trimmed the stems a few times. Many passers by comment on it. It's just a bit different to other things I've had before and has done better.
I agree Craft,I spent a massive amount of money on 2 lovely buxus trees,they were great for 4 years and both suddenly went brown and died.I was gutted! My Vinca cost £5 from a local nursery.Brilliant.