Lemon and salt works pretty well. Cut a lemon in half, dip the cut end in salt and scrub away. The acid breaks up the gunk and cuts grease and the salt is the scrubbing agent.
We bought a steam cleaner-- not a handheld one, but a little vacuum-cleaner sized one-- for less than £25 on ebay. It shoots a jet of hot steam. I've used it to clean the oven. The first time you do it you kill about 400 scouring pads and cloths, but following up every 6 weeks really keeps things shiny. Like "we-don't-use-the-oven" shiny.
We also use the steam cleaner in the bathroom-- it disinfects the toilet, gets rid of mildew, etc.-- twice a month. It has more than paid for itself.