I grew up in a village so getting out of the city centre matters to me. I've been converted to town/city life having lived in Bath, Reading and Exeter for the last 12 years, but I have to get out sometime!
In Exeter this is made spectacular by two things. First there is the domitory town / suburb of Topsham. A short drive from the ring road or an easy train ride away this is the best place to spend a Saturday morning. On arrival the Antiques centre is worth a browse followed by a walk along The Strand, parallel to the river, and then out along the esturary for a while. On returning The Cafe on Fore Street is a great place to sit with your wife and drink coffee, chat and read the paper - a newsagent is opposite. Returning home with as slight detour to Darts Farm is no bad idea.
On the otherside of the river Exe, at the end of the canal is the Turf pub at Turf Locks. Inaccessible by road, you can park just under a mile away at the of Station Road, Exminster. Alternatively walk the five miles from The Quay, via Double Locks down to Turf Locks along the canal, or take a ferry from Topsham. A great place to go on an afternoon or an evening. On arrival, sitting in the garden looking down the river and out to sea is brilliant, views of Topsham and Exmouth on the other side of the river.