Lasagne is a good one and easy to sort cooking-wise (some garlic bread is handy to have frozen too).
Smoked haddock and brocolli pie (topped with mash potato, breadcrumbs, and grated cheese) freezes well too.
Pasta bake - pasta shapes left al dente with a cheese sauce and lots of veggies (fried mushrooms, fried onions and garlic, courgettes cooked with pasta for the last few mins, sweet peppers, peas, mange tout or sugar snaps, etc) and chopped bacon/ham - we make a huge pot of this to eat straight from the pot as "macaroni cheese", and freeze any leftovers to reheat and eat as "pasta bake" with a little grated cheese over the top.
Other dishes that we freeze and heat on the hob but have done in the freezer include:
Spag bol
Curries - rogan josh (lamb), chicken bhuna or chicken jalfrezi are all nice.
CHilli con carne is DH's addition to the freezer.
Another good one that is for the oven but from store cupboard items (and takes 3 minutes to prep - seriously) is chorizo potatoes. In a large bowl or the oven-proof dish, mix together 1 bag of salad baby potatoes, 1 jar of tomato and chilli sauce (we like the Sacla one with whole cherry toms), chopped chorizo (we use half of a U-shaped one from Lidl) and some bacon pieces (optional, we use 1 of the 2-portion pack from Lidl, using leftover Christmas ham works well too). Stir together, (put on oven-proof dish if necessary) and roast at 180 degrees C for 1 hr (or until spuds cooked through). Serve with creme fraiche (to take down heat for delicate palates).