I like to visit battlefields too...all English so far though.

Marston Moor, 1644, has a nice monument and guide to the largest pitched battle of the ECW. Close to it is the biggest battle in the Wars of the Roses... Towton, 1461, nicely accessible and topographically rewarding, the local church is also worth a visit, as it has the grave of Lord Dacres, allegedly buried on his horse.
Hastings, 1066, I've done re-enactment stuff here, it's quite good but a bit touristy, lots to see though the actual field is a bit over grown as I recall.
Flodden, 1513, panoramic but the weather was awful.

Many of England's battlefields are now covered with housing estates sadly, I'd like to visit the ACW ones, and perhaps also some of the major Peninsular war fields, many of which seem to be in good condition.