As an owner of all the current gen systems (360, PS3, Wii, and older systems like PS2, PS1, Xbox, Dreamcast, Saturn, Genesis, Gamecube, N64), I'd have to say it depends on what kind of games you like to play and if there are any exclusive franchises that you favor. Also, do any of your friends have gaming consoles? If so, it may be worthwhile to get the same one so you can borrow/lend games to each other or play together.
Since you say that you doubt that you will play online then the value of free online play of the PS3 vs paid Xbox Live is equally useless to you. Same with the PS3's built-in WiFi vs $75 add-on WiFi of the 360.
As for reliability.... PS3 hands down. I'm on my 4th 360, 2 RRoDs and 1 dead DVD drive took out the first 3. My 3 year RRoD warranty is gone so once this one dies, that's it. I'd have to buy a replacement, probably an Arcade since I've got a 120GB HD. A few of my co-workers also own 360s (6 of them) and every single one of them has had to send theirs back at least once (one has sent his back twice). These are all older 360s though, none of us have the newer Falcon & whatever the newest motherboard revision is called 360s. 4 of my co-workers have PS3s (1 also has a 360) and they all work fine, from the initial launch 20GB & (2x) 60GB models, to the latest no-PS2-emulation 80GB model. I've got the 80GB MGS4 bundle PS3 w/partial PS2-emulation.
We've got about 10 PS3 games and about 40+ 360 games. I share the 360 with my younger brother and he's the one with the Live account since all his friends also have Live accts and they play online all the time. I honestly don't game much on my PS3. I've got a few exclusives for it (MGS4, Little Big Planet, Killzone 2, Resistance 1 & 2, Infamous) but honestly, it's not that much better/different than FPSes on the 360 (Halo, Gears of War, etc). I use the PS3 primarily as my media & blu-ray player. I have the
PS3 Media Server software running on my main PC that streams all my movies, music, & photos to my PS3 via gigabit LAN (it also streams to the 360 now, though I find it scales & looks better on the PS3). Works great, plays any and everything that I can throw at it, divx, xvid, mkv, rmvb, mov, mp4, etc.
Most of the big AAA titles are released on both platforms nowadays so really, your decision should be based on which exclusive platform specific titles that you want to play.
One other minor thing that bugs me is the batteries for the controllers. The 360 uses 2xAAs, and I've got a minor stockpile of Eneloops I can swap them out at will in about 10 seconds. We also had a MS play & charge kit, who's NiMH have now died (can't hold a charge for more than 1 day) so I'm glad I don't have to throw the whole controller out. The PS3 Dual-Shocks use built-in Li-ions, so when those cells die, I'd have to chuck out the entire controller ($50). I also have to plug it into the PS3 when the batteries are low so if you have a short USB cable, it's gonna suck when you're trying to charge & play at the same time on a big screen with a short 4ft cable. You can buy a 8-10ft USB cable to mitigate this. Also the PS3 does NOT charge the controller if it's in off or standby mode. So you have to keep the PS3 on to charge them. You can of course by a 3rd party stand-alone controller charger but knowing what I know about good & bad li-ion chargers now, I'm not too confident in the quality of those cheap $15-20 chargers. Too bad I can't hook up my Pila IBC charger to it.
One other thing that I should mention. If a game is released on both platforms, paid/free DLC will come out either simultaneously (Call of Duty map packs) or on the 360 first, depending on the title. For example for Fallout 3, there have been 3, maybe 4 map/add-on packs released for the 360 version now, but still none for the PS3 version yet. So that's something else to consider, but it will vary depending on the game.
So after all is said and done, I would still consider the 360 to be the better gaming platform even though the hardware is flawed (evidenced by my possesion of a 4th replacement unit). The PS3 is the better media/blu-ray playing/streaming platform that happens to also play games.