My favorite budget hotel in the Disneyland vicinity is Majestic Gardens. It's not across the street, but they their own dedicated shuttle that picks up at the front of the hotel, and drops off at the transportation plaza. It's like an 8-ish minute ride each way. The reasons it's my go-to: $130-140/night when booked directly, clean property, beautiful resort feel, huge rooms, comfy beds, friendly staff, interior corridors. Sometimes I'll pay $20 more a night for an upgraded room, which is even bigger, with a couch, chair, coffee table. It's generally fairly quiet, though if you have a connecting room, it's less so. I've stayed at 9 motels in the area (Fairfield, Tropicana, Park Vue Inn, Desert Inn, Legacy Grand, Stovall's, King's Inn, Discovery, and Majestic) and since I tried Majestic, I haven't gone anywhere else.