The GTA games are TOO large, if you ask me. Oblivion was around the right length for me because I felt like I was genuinely exploring. The GTA games were so goddamn large, but there's no variety in it. Drive, shoot things, drive, shoot things for a different reason, steal a new car, shoot things because you feel like it, rob a bank, shoot things, steal a car. I really tried to like them, but I just couldn't find a reason to keep playing after 15 minutes.
15 minutes?
[Your list sounds like GTA1? I only started with Vice City.]
.......I wonder if you got far enough in San Andreas to:
collect and use the GOOD weapons (hint: they're nowhere near CJ's house)
jump off a 90-story building with a parachute
race a
bicycle down an insanely steep mountain path
gather homies and spark gang wars (& later defend your turf when they counterattack)
fly a P-51 Mustang or an aerobatic plane
(every single vehicle in the game handles differently) do the ambulance missions against the clock (handles surprisingly well when you get the hang of it)
(not to mention the firetruck, vigilante, taxi, delivery and pimping side-missions)
play several "real" games in casinos & bars, that win/lose your in-game money (even billiards! done pretty well, too)
try the 3 hot motorcycles (I found them MUCH better than cars for speed, outmaneuvering cops, jumping things and FUN)
drive several different boats in and out of boating school
fly big & small helicopters (under bridges, between skyscrapers, scaring beachgoers, etc)
pump iron, outfit your CJ in rad threads, tatts & afro and date the 6 girlfriends (each wants different things and gives unique rewards)
drive in a crazy demo derby in a special stadium
drop satchel charges on wave after wave of SFPD
capture and drive the M1 Abrams tank
through San Francisco or Las Vegas, it's hella fun blowing up everything in sight
or fly around with
the jet-pack! It's a damn good prize for a late mission.
Did you get to fire the (amusingly misnamed) Minigun? My personal favorite. And yes, I liked the flavor of Vice City better, but SA improved a lot AND added a whole lot - it was like they tried to include everything we wanted, and polished everything to work better.
There's much more, but these give some idea of the variety. And
NONE of the above examples are from the 100 storyline missions. There's lots more variety there: assassinate with sniperscope; bounce low-riders and dance in a club (both like DDR); plan and pull a heist in a major casino; steal Police motorcycles and drive them onto a car-carrier truck barreling down the highway; fly radio-contolled biplanes; parachute onto a bizjet, take it over and fly it home; swim underwater out to a heavily guarded boat with only a knife and free some hostages; shoot down evasive hostile helicopters with heat-seeking missiles; drive a motorcycle around an insane 3D course inside a big drydock; operate radio-controlled helicopters inside a geek's dream war simulator; sneak aboard an aircraft carrier and steal a Harrier, then defend yourself vs enemy Harriers using HUD radar targeted guided missiles; team-jump out of a C-5 and paraglide onto a helipad to take over a drug lord's mansion; rescue a girl from a burning, smoke-filled building; they really went for variety in San Andreas.
And I had hours of fun just genuinely exploring, too. There's a secret military base (with an underground black project that you can steal!) and an abandoned airfield out in the desert... and much more.