With that you risk losing your forces and giving them time to mount a counterassault.
If you're GDI You can...:
a) Be strategic and mechanically take them out. Launch a Wing of about 15 Fighters to take out the EMP, air, and ground defenses, followed closely by a strike team of about 9 bombers, four targeting the Construction Yard, Three targeting the War Factory and Two to strike the Hand of Nod. This will cripple their production. Once the defenses are taken out, a massive ground invasion follows. Two Disruptors followed by six Titans to take down any armoured units in the base. Mop up the base with wolverines and Infantry. If by now the opponent doesn't surrender, cripple their superweapons by destroying their Power Production Facilities and fall back and let them suffer. (yes, be sadistic). If you wish to end it, finish them off with your Titans.

Launch a Blitzkrieg. First launch an air assault. 20 fighters to mop up mobile units while the bombers concentrate on stationary targets (Production Facilities, Financial facilities, EMP Cannons, ect) Then launch a massive ground assault. From the
North, send a force consisting of 8 Disruptors, A Mammoth MKII, 20 Titans, 15 Wolverines, 25 Disk Throwers and 25 Light Infantry. From the South, flank them with a Mammoth MKII, followed by 15 Titans, 15 Wolverines, 20 Disk Throwers and 20 light Infantry. Try to protect the Construction Yard until you can get an AAPC via Carryall in there to capture it, then have the Construction Yard undeploy into it's Mobile form, and have the carryall pick it up and haul ass back home. (this is if you have other enemies)
c) Force them to surrender using diplomacy and a bit of force. Build up a huge attack force, 30 Disruptors, 50 Titans, 50 Wolverines, 15 AAPC's Filled with all types of Infantry, 100 or so Infantry of all types, a stout base defense, as well as several forward production bases and defensive bases strategically placed at chokeholds and throttle points throughout the map. Set these forces in a nice formation outside of their base's range of fire and surround them. Start negotiating peace talks, which should look something like this (I did this with my brother).
QUOTE
TSRdaTS: You are surrounded. Surrender your MCV now and you will not be attacked.
Fearless92: I could always EMP your stupid force.
TSRdaTS: Think Again
*Sends in bombers to strike EMP cannon*
TSRdaTS: By the time you rebuild and charge up, I can strike again and again.
TSRdaTS: I can do this for ages.
Fearless92: Wow, you really are determined aren't you?
Fearless92: So what do you want with my MCV?
TSRdaTS: I wish to construct a joint strike base to attack you later en masse.
Fearless92: Oh... That's not fair. In fact, it's Humilating.
TSRdaTS: You could always surrender.
Fearless92: I think I'll do that.
- Fearless92 has surrendered.
- You are Victorious.
If you're Nod, then you can...:
You can just load up a bunch of SubAPC's with engineers and place them near the structures, once there, deploy, capture, and sell the entire base right out from under their nose.
Yeah, i'm pretty strategic.