www.drivethrurpg.com
That's the same one I was going to suggest: FFG's
End of the World: Alien Invasion
That said, the timeline is great, the rules are very light, and it's exactly what it promises.
The other 3 titles are also the same rules, same format. I want to get it to table, but I want to use Rise of the Machines.
TORG, either edition, is a variation, in that it's interdimensional and it involves imposing their own realities, and they're multiple factions only loosely allied... for the time being...
The other ones I know of are not the classic War of the World/Mars Attacks type scenario...
Starchildren: Velvet Generation is aliens come to restore rock and roll to a dictator ruled dystopia where rock is banned.
Burning Wheel: Jihad is essentially the Fremen invasions with the serial numbers filed off. Yeah, it's Dune in all but name. It's a setting for BW Revised, but can be used with BWG or BWC just fine.
Burning Empires is Chris Moeller's
Iron Empires done as a variant on BW and Jihad. Essentially Stargate's Goa'uld but with less egomanaiacal BS, and Classic Traveller's ship paradigms. It is a standalone.
Note: both Jihad and BE use a variation on the Duel of Wits mechanic to handle the invasion timelines, so it's totally not going to be that useful to JD.
Hunter Planet: The All Australian Role Playing Game This is basically Predator in humor mode... the hunters look like stuffed animals and are dropped in pre-gun-buyback Australia... with high tech zap guns. The sample adventure is in Sydney... It's hilarious, but also it's out of print long ago last I heard. No timeline, the invasion is simply hunting expeditions.