Are you really into the nitty-gritty of Latin Grammar? If you are, then I would recommend Completely Parsed Cicero. If you scroll through the 'Look Inside' feature on Amazon, you will see the actual page layout. A HUGE amount of grammatical data on every single word, but also a literal and literary translation. You will learn more than you ever wanted to know, plus that speech, for my money, is one of his most interesting.
https://www.amazon.com/Completely-Parsed-Cicero-Oration-Catiline/dp/0865165904.
If you don't want to go so deep, then the Legamus series are very good for getting a taste of an ancient author, plus they will revise a lot of the grammatical features that you encountered at School. Here is the Horace one, for example.
I definitely second gelato's recommendation of Lingua Latina per se and Beyond GSCE.
And, of course, you should be reading Legonium. ;)