It is not really cheating as this is something that the gameplay allows, so I consider it much better than using Motherlode!
1) Go to the future
2) Go to the city hall and check the lotto records
Sims won’t always be successful in getting the records and will have to try again. You need the insider tips moodlet for this to work.
3) Go back to the present and buy lotto tickets at the grocery store.
You can buy as many as you want, I seem to have gotten bigger prizes when I bought several tickets.
4) Then after about a Sim day if you won your Sim will get a big check.
My Sim has won 115k once and 1.5M twice. A higher Advanced Technology will help you win bigger.